JP2011071595A - Communication control device, control method and control program of communication control device, and computer readable recording medium having the control program recorded therein - Google Patents

Abstract

A data flow is transmitted by lowering the priority of a data flow that is not subject to QoS.
A HGW 101a extracts a packet distribution processing unit 141 that extracts a communication address of a transmission source and a communication address of a transmission destination from a communication packet of a data flow transmitted from an access network 702 to a home network 501; When a pair of the original communication address and the destination communication address is not stored in the queue assignment information storage unit 23, a packet transmission processing unit 142 that transmits the data flow to the home network 501 at a lower priority. Is provided.
[Selection] Figure 1

Description

  The present invention relates to a communication control apparatus that performs QoS (Quality of Service) control of a data flow, a control method for the communication control apparatus, a control program, and a computer recording the control program in a communication network that simultaneously transmits a plurality of data flows. The present invention relates to a readable recording medium.

  In recent years, a data flow (hereinafter referred to as a real-time data flow) provided by a content providing device such as a content server installed on the Internet, which needs to be transmitted in real time, such as video and audio, is referred to as a STB (Set Services that can be received by a receiving device such as a top box), a television, and a VoIP (Voice over Internet Protocol) receiver are provided. These services generally use streaming transmission in which data is reproduced while being downloaded by a receiving device. Since video data is generally large in size, when playback starts after downloading is completed on the receiving device, the time required from the user instructing video reception until the video can be viewed increases. Convenience will be impaired. Therefore, streaming transmission is necessary to shorten the waiting time until viewing becomes possible and improve convenience. Also, in voice calls, in order to establish a conversation, it is necessary to transmit the voice uttered by the user to the other user without delay, so streaming transmission is necessary.

  By the way, the data flow transmitted from the content providing apparatus is temporarily transmitted via an access network provided between the service provider base station and the user's home, such as an IP (Internet Protocol) network or an NGN (Next Generation Network). After being received by a router such as an HGW (Home Gateway), it is further transmitted to an STB, a television, etc. via a LAN (Local Area Network) (hereinafter referred to as home network) built in the user's home.

  In many cases, terminals such as PCs (Personal Computers) are connected to the home network in addition to receiving devices such as STBs and televisions. In PCs, not only real-time data flows, but also data flows that do not need to be transmitted in real time, such as browsing web contents on the Internet, sending and receiving e-mails, and transferring data by FTP (File Transfer Protocol) Real-time data flow) can be received from a server device installed on the Internet. Even in this case, the data flow transmitted from the server device is transmitted to the PC via the access network, the HGW, and the home network.

  A data flow refers to a series of data that needs to be transmitted continuously. A series of data that needs to be transmitted continuously is, for example, a meaningful group of data such as one video content or one audio content. Therefore, a plurality of packets belong to one data flow. In addition, a packet is data in which data is assembled into a frame of a predetermined format, and various information such as a destination address is added to the frame. Data transmission / reception between devices is generally performed by packet communication that carries data by packet transmission / reception.

(QoS technology)
By the way, in the transmission of the non-real time data flow, even if a certain amount of transmission delay or jitter (transmission delay fluctuation) occurs, the data reproduction in the receiving apparatus is not greatly affected. For example, even if a transmission delay or jitter occurs during downloading of data by FTP, the time until the download is completed is delayed, but there is no influence of the transmission delay or jitter when using the downloaded data.

  On the other hand, in the case of streaming transmission of a real-time data flow, the transmission delay and jitter lead to disturbance of the reproduction of video and audio at the receiving apparatus, so it is necessary to keep them within a predetermined range. That is, in order for the receiving device to receive the real-time data flow from the content providing device at high speed and with high quality, the transmission quality of the packet of the real-time data flow is appropriate in each network where the real-time data flow is transmitted. Must be secured.

  As described above, a technique for simultaneously and efficiently transmitting a plurality of data while ensuring appropriate quality according to the type of data to be transmitted is referred to as a QoS (Quality of Service) technique. The QoS technology is roughly classified into priority control type QoS (Prioritized QoS) and parameter guaranteed type QoS (Parameterized QoS). By using mechanisms such as priority control type QoS and parameter guarantee type QoS as basic technologies, access contention in the entire communication network can be avoided and QoS can be realized.

(Priority control type QoS)
In priority control type QoS, a communication device that transmits data gives priority to the packet of transmission data according to the type of data and the characteristics of the communication device that transmits and receives data. And QoS is implement | achieved by controlling transmission data based on the priority provided to the packet. As a method of assigning priority to packets, a field for storing a value indicating priority (hereinafter referred to as a priority field) is provided in advance in the header portion of the packet. A method of setting a value is common.

  For example, since real-time data requires higher transmission quality than non-real-time data, a higher priority value than a non-real-time data packet is set in the priority field for real-time data packets. It is common. The transmission apparatus or the relay apparatus on the communication network determines the packet transmission timing based on the value of the priority field of each packet, thereby realizing QoS.

(Transmission of data flow in access network)
Next, an example in which the transmission quality of packets in a real-time data flow is not ensured appropriately will be described. Here, a use case is assumed in which a real-time data flow is received by a receiving device such as an STB or a television on the home network and a non-real-time data flow is received by a terminal such as a PC on the home network.

  The real-time data flow is usually transmitted at a substantially constant transmission rate (transmission band). On the other hand, non-real-time data flows are often transmitted using the communication network's line capacity (line speed, transmission bandwidth) as much as possible. In other words, the transmission is often performed so that there is as little space as possible in the transmission band of the communication network. However, transmission does not exceed the upper limit of the line capacity of the communication network having the smallest line capacity (narrow transmission bandwidth) on the transmission path. In addition, since the specific transmission method of a non-real-time data flow is dependent on mounting of a receiver or a transmitter, description is abbreviate | omitted for the detail.

  Therefore, when the real-time data flow and the non-real-time data flow are transmitted at the same time on the same communication network as in the assumed use case, the transmission band other than the transmission band used by the real-time data flow is It will be occupied by non-real-time data flow, and normally there will be no vacancy in the transmission bandwidth of the communication network.

  In this state, if the transmission rate of the real-time data flow increases momentarily (temporarily), the total of the transmission rate of the real-time data flow and the transmission rate of the non-real-time data flow exceeds the line capacity of the communication network. Become. As a result, transmission delay and jitter of real-time data are generated, and there is a problem that video and audio reproduction is disturbed in the receiving apparatus. In particular, in the access network, since the line capacity is generally small compared to the Internet upstream and the home network downstream thereof, the above problem is likely to occur.

  With reference to FIG. 15A, a description will be given of how the transmission band is insufficient when a plurality of data flows are transmitted on the access network. FIG. 15A is a diagram illustrating an example of temporal transition of a transmission band used by each data flow when two types of data flows are transmitted on the access network. Here, it is assumed that the line capacity of the access network is 70 Mbps (bits / second). In the following, the data flow of video content and the data flow of FTP are also referred to as “video data flow” and “FTP data flow”, respectively.

  First, at time T51, it is assumed that a video data flow that is a real-time data flow and an FTP data flow that is a non-real-time data flow are transmitted. At this point, it is assumed that the video data flow uses a transmission band of 10 Mbps and the FTP data flow uses a transmission band of 60 Mbps. In this case, at time T51, the total transmission bandwidth used by the video data flow and the FTP data flow is the same as the line capacity of the access network, and the transmission bandwidth of any data flow is not insufficient. Therefore, transmission delay and jitter do not occur, so that reception data is not lost in a receiving apparatus that receives each data flow, and data reproduction is not disturbed.

  Next, at time T52, as shown in the figure, it is assumed that the transmission rate of the video data flow temporarily increases and the transmission rate of the FTP data flow temporarily decreases. However, even at time T52, the total transmission bandwidth used by the video data flow and the FTP data flow is the same as the line capacity of the access network, and therefore the transmission bandwidth of any data flow is not insufficient.

  Next, at time T53, as shown in the figure, it is assumed that the transmission rate of the video data flow remains the transmission rate at time T52, but the transmission rate of the FTP data flow has returned to the transmission rate at time T52. In this case, the total transmission bandwidth used by the video data flow and the FTP data flow is larger than the line capacity of the access network. That is, since the transmission band is insufficient, for example, transmission delay and jitter occur in the video data flow. As a result, video and audio reproduction disturbance occurs in the video data flow receiver.

  When the two types of data flows transmitted on the access network described with reference to FIG. 15A are transmitted on a communication network having a larger line capacity than the access network, problems such as transmission delay occur. Absent. Referring to FIG. 15B, the two types of data flows transmitted on the access network described with reference to FIG. 15A are transmitted on a communication network having a larger line capacity than the access network. explain.

  As shown in the figure, the total transmission bandwidth used by the video data flow and the FTP data flow at any time is sufficiently smaller than the line capacity of the communication network, and there is a vacancy in the transmission bandwidth of the communication network. It is. This is because the total transmission bandwidth used by the video data flow and the FTP data flow does not exceed 70 Mbps, which is the line capacity of the access network.

  Thus, problems such as transmission delay do not occur in a communication network having a larger line capacity than the access network. Therefore, since the Internet and home network usually have a larger line capacity than the access network, problems such as transmission delay do not occur even if the transmission rate of the video data flow and the FTP data flow is slightly increased or decreased.

(Prior art)
As a technique for improving the reproduction quality of video and audio reproduction in the receiving device, the content server serving as the service site sends the content to the terminal device at the content transmission speed (compression rate) determined according to the communication speed of the terminal device. Japanese Patent Application Laid-Open No. H10-228688 discloses a technique for transmitting data to the Internet. In Patent Document 1, content is transmitted to a terminal device according to the following procedure. (1) When the terminal device transmits terminal data that can identify the communication line to the communication speed server, the communication speed server identifies the communication speed of the terminal device based on the terminal data. (2) The communication speed server transmits the identified communication speed to the terminal device, and the terminal device transmits the communication speed to the content server. (3) Then, the content server determines the transmission speed of the content to the terminal device based on the communication speed, and transmits the content to the terminal device at the determined transmission speed.

Japanese Patent Laying-Open No. 2005-130134 (Publication date: May 19, 2005)

  In the technology disclosed in Patent Document 1, a content server that is a service site needs to have a function of changing a content transmission speed (compression rate). Therefore, the technology disclosed in Patent Document 1 cannot be applied to a service site that does not have the above function. Since it is virtually impossible to provide all the service sites with the above functions, the content transmitted from all the service sites accessed by the receiving apparatus is reproduced using the technique disclosed in Patent Document 1. There is a problem that quality cannot be improved.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to control a communication control device and a communication control device that transmit the data flow by lowering the priority of a data flow that is not a target for securing QoS. A method, a control program, and a computer-readable recording medium on which the control program is recorded.

  In order to solve the above problems, a communication control device according to the present invention is connected to a first communication network to which a data receiving device is connected and a second communication network to which a data transmitting device is connected, and the data transmitting device is A communication control device for controlling transmission of a data flow composed of a plurality of communication packets to be transmitted to a data receiving device to the first communication network, wherein each communication packet constituting the data flow is the communication The communication address of the data transmission device that is the transmission source of the packet and the communication address of the data reception device that is the transmission destination of the communication packet, and the communication address of the data transmission device and the communication of the data reception device From the first storage unit that stores the addresses in advance in association with each other, and the communication packet that constitutes the data flow, A source address / destination address extracting means for extracting a source communication address and a destination communication address, and the source communication address and the destination extracted by the source address / destination address extracting means When the pair with the communication address is not stored in the first storage unit, the data flow transmitted from the data transmission device to the data reception device is transmitted to the first communication network at a lower priority. And a data flow transmission control means.

  The communication control apparatus control method according to the present invention is connected to a first communication network to which the data receiving apparatus is connected and a second communication network to which the data transmitting apparatus is connected. The first communication of a data flow comprising a plurality of communication packets, which includes a first storage unit that stores in advance associated with a communication address of the data receiving device, and that the data transmitting device transmits to the data receiving device. A communication control device control method for controlling transmission to a network, wherein each communication packet constituting the data flow includes a communication address of the data transmission device that is a transmission source of the communication packet, and the communication packet It contains the communication address of the data receiving device that is the transmission destination, from the communication packet that constitutes the data flow The source address / destination address extraction step for extracting the source communication address and the destination communication address, and the source communication address extracted in the source address / destination address extraction step When a pair with a communication address of a transmission destination is not stored in the first storage unit, the data flow transmitted from the data transmission device to the data reception device is reduced in priority to the first communication network. And a data flow transmission control step for transmission.

  According to said structure, the communication address of a transmission source and the communication address of a transmission destination can be extracted from the communication packet which comprises the data flow which a data transmission device transmits to a data reception device. Then, when the pair of the extracted communication address of the transmission source and the communication address of the transmission destination is not stored in the first storage unit, the data flow transmitted from the data transmission device to the data reception device is reduced in priority. To the first communication network.

  Therefore, when the data transmission device transmits the data flow to be transmitted to the data reception device to the first communication network, the set of the communication address of the transmission source and the communication address of the transmission destination of the communication packet constituting the data flow is the first. When the data is not stored in one storage unit, the data flow can be controlled to be transmitted with a lower priority. In other words, when a set of a communication address of a transmission packet and a communication address of a transmission destination of communication packets constituting the data flow is stored in the first storage unit, the data flow is transferred to the first communication network. Is transmitted without lowering the priority of the data flow. As a result, the data flow transmitted without lowering the priority can be transmitted to the first communication network with higher priority than the data flow transmitted with the lower priority.

  Here, in a situation where data flows transmitted from each of a plurality of data transmission devices are transmitted on the same communication network, if each data flow is transmitted without controlling the priority, it is listed in the background art column. As described above, a transmission delay or jitter may occur when the transmission rate of any data flow increases momentarily or temporarily. For example, non-real-time data flows such as FTP data flows are usually transmitted at a transmission rate (transmission band) that uses the maximum line capacity of the communication network, while real-time data flows such as video data flows are usually It is transmitted at a substantially constant transmission rate (transmission band). Therefore, in a situation where the video data flow transmitted from the video distribution server and the FTP data flow transmitted from the FTP server are transmitted on the same communication network, the transmission rate of the video data flow is instantaneously or temporarily. In the case of increase, the total of the transmission rate of the FTP data flow and the transmission rate of the video data flow may exceed the line capacity of the communication network, and in this case, transmission delay or jitter of the video data flow may occur. is there.

  However, according to the present invention, data flow that does not need to be preferentially transmitted (not subject to securing QoS) is lowered in priority and data that needs to be preferentially transmitted (subject to secure QoS). Since the priority of the flow is not lowered, as a result, it is possible to preferentially transmit a data flow that needs to be preferentially transmitted (target for ensuring QoS). That is, for example, the priority of the FTP data flow transmitted from the FTP server is lowered, and the priority of the video data flow transmitted from the video distribution server is not lowered. As a result, the video data transmitted from the video distribution server is reduced. A flow can be transmitted with priority.

  Therefore, according to the present invention, it is possible to preferentially transmit a data flow that is a target for securing QoS in a communication network that transmits a plurality of data flows simultaneously. For example, in a communication network that simultaneously transmits a video data flow and an FTP data flow, a video data flow that is easily affected by transmission delay, jitter, and the like is transmitted preferentially over an FTP data flow. Since it is possible to suppress the occurrence of transmission delay, jitter, and the like, it is possible to suppress the occurrence of disturbance in the reproduction of video and audio in the data receiving apparatus that receives the video data flow. That is, there is an effect that QoS of a real-time data flow such as a video data flow can be secured.

  Furthermore, when a data flow is transmitted using a communication protocol in which the transmission amount of communication packets can be controlled by a data transmission device by generally known window control, QoS is to be secured. The data flow can be transmitted more preferentially and will be described below.

  In the data receiving apparatus that receives a data flow transmitted with a lowered priority according to the present invention, the reception amount of packets belonging to the data flow is reduced as compared with the case where the priority is not lowered. In response to this, the amount of ACK (acknowledge) packets to the data transmitting device for the reception of the packet by the data receiving device is reduced. As a result, in the data transmission apparatus, control is performed to suppress the transmission amount of the data flow whose priority is lowered. That is, the transmission rate at the time of sending the data flow from the data transmission device to the second communication network is lowered. Therefore, the transmission bandwidth of the second communication network is emptied by the reduced amount, so that the data flow whose priority is not lowered (need to be transmitted preferentially) uses the vacant transmission bandwidth. Is possible. Therefore, even if the transmission rate of the data flow whose priority is not lowered (need to be transmitted preferentially) increases momentarily or temporarily, there is a high possibility that the line capacity of the second communication network will not be exceeded. As a result, the QoS of a real-time data flow such as a video data flow whose priority is not lowered can be more reliably ensured.

  Furthermore, the communication control apparatus according to the present invention may be configured such that the data flow transmission control means transmits the data flow transmitted at a lower priority at a transmission rate that does not exceed a predetermined limit value.

  According to said structure, the data flow transmitted to a 1st communication network by lowering | hanging a priority can be further transmitted to a 1st communication network with the transmission rate which does not exceed a predetermined | prescribed limit value.

  Therefore, the data flow transmitted to the first communication network without lowering the priority can be transmitted without limiting the transmission rate. As a result, the data flow transmitted without lowering the priority can be transmitted to the first communication network preferentially over the data flow transmitted at the transmission rate not exceeding the limit value.

  Therefore, in a communication network that transmits a plurality of data flows at the same time, there is an effect that a data flow that is a target for ensuring QoS can be preferentially transmitted.

  Furthermore, the communication control apparatus according to the present invention includes a second storage unit that stores in advance, for each data flow, a transmission rate necessary for transmitting the data flow to be preferentially transmitted, and the second storage unit. A third storage unit for preliminarily storing the line capacity of the communication network, a priority packet holding unit for temporarily storing the communication packet of the data flow to be preferentially transmitted, and the source address / destination address When the pair of the communication address of the transmission source and the communication address of the transmission destination extracted by the extraction unit is stored in the first storage unit, the communication packet of the data flow is stored in the priority packet holding unit. The communication packet storage means for storing, and the transmission of each of the data flows composed of the communication packets stored in the priority packet holding unit. Priority transmission rate calculation means for acquiring a rate from the second storage unit and calculating a total value of all the acquired transmission rates, and a line capacity of the second communication network stored in the third storage unit The transmission rate calculation unit may further include a transmission rate calculation unit that calculates the limit value by subtracting the total value calculated by the transmission rate calculation unit.

  According to the above configuration, when the pair of the communication address of the transmission source and the communication address of the transmission destination extracted by the transmission source address / destination address extraction unit is stored in the first storage unit, the data The communication packet of the flow can be stored in the priority packet holding unit. And each transmission rate of the data flow comprised from the communication packet stored in the priority packet holding | maintenance part can be acquired from a 2nd memory | storage part, and the total value of all the acquired transmission rates can be calculated. Then, the limit value can be calculated by subtracting the calculated total value from the line capacity of the second communication network stored in the third storage unit.

  Therefore, it is possible to transmit a data flow that is not a target for preferential transmission to the first communication network at a transmission rate that does not exceed the limit value. That is, a data flow that needs to be transmitted with priority can be transmitted to the first communication network in a state where a necessary transmission band is secured.

  Therefore, there is an effect that the QoS of the data flow that needs to be preferentially transmitted can be ensured more reliably.

  In particular, when the line capacity of the second communication network is smaller than the line capacity of the first communication network, the first communication network transmits the data flow transmitted with lower priority at a transmission rate not exceeding the calculated limit value. By transmitting a data flow that needs to be transmitted preferentially and transmitted to the first communication network without limiting the transmission rate, each data can be transmitted in both the second communication network and the first communication network. The possibility that the total value of the flow transmission rates exceeds the line capacity of the second communication network is reduced. Therefore, it is possible to more reliably suppress the occurrence of transmission delay, jitter, etc. of the data flow that needs to be transmitted preferentially. For example, in the data receiving device that receives the video data flow, the occurrence of disturbance in the reproduction of video and audio There is an effect that can be suppressed more reliably.

  Further, in the communication control apparatus according to the present invention, the data receiving apparatus transmits a first request for requesting a communication address of the data transmitting apparatus, and communication of the data transmitting apparatus included in a response to the first request. Based on the address, a second request for requesting the data flow is transmitted to the data transmission device. The data transmission device belongs to a domain, and the data flow is transmitted as a response to the second request. The first request includes a domain name of a domain to which the data transmission device belongs and a communication address of the data reception device, and the first storage unit is configured to transmit the first request to the data reception device. Corresponding to the communication address of the data transmitting device associated with the communication address of the data receiving device Further, the domain name of the data transmission device is stored, and the second storage unit sets a transmission rate necessary for transmitting the data flow to be preferentially transmitted to the data flow. A domain name / address extracting means for extracting the domain name of the data transmitting device and the communication address of the data receiving device from the response; Address acquisition means for acquiring the communication address of the data transmission apparatus associated with the domain name of the data transmission apparatus extracted by the domain name / address extraction means; and the data extracted by the domain name / address extraction means When the domain name of the transmitting device is stored in the second storage unit, the address acquisition means takes Transmission control information generating means for storing the communication address of the data transmitting apparatus and the communication address of the data receiving apparatus extracted by the domain name / address extracting means in association with each other and storing them in the first storage unit. The priority transmission rate calculation means obtains the domain name of the data transmission device associated with the communication address of the transmission source of the communication packet stored in the priority packet holding unit from the first storage unit. In addition, for each acquired domain name, the transmission rate associated with the acquired domain name is acquired from the second storage unit, and the total value of all the acquired transmission rates is calculated. Also good.

  According to the above configuration, the domain name of the data transmission device and the communication address of the data reception device can be further extracted from the response. Then, the communication address of the data transmission device associated with the extracted domain name of the data transmission device can be acquired. Further, when the domain name of the extracted data transmission device is stored in the second storage unit, the communication address of the extracted data reception device is associated with the communication address of the acquired data transmission device, It can be stored in the first storage unit. In addition, the domain name of the data transmission device associated with the communication address of the transmission source of the communication packet stored in the priority packet holding unit is acquired from the first storage unit, and for each acquired domain name, The transmission rate associated with the acquired domain name can be acquired from the second storage unit, and the total value of all the acquired transmission rates can be calculated.

  Therefore, when the data flow transmitted from the data transmission device as a response to the second request is transmitted to the first communication network, if the domain name of the data transmission device is not stored in the second storage unit, the data transmission Since the set of the communication address of the device and the communication address of the data receiving device that has transmitted the second request is not stored in the first storage unit, the data flow can be transmitted at a transmission rate that does not exceed the limit value. it can. In other words, when the domain name of the data transmission device is stored in the second storage unit, when transmitting the data flow transmitted from the data transmission device to the first communication network, the transmission rate is not limited. Since the data flow can be transmitted, the data flow can be transmitted to the first communication network with higher priority than the data flow transmitted at a transmission rate not exceeding the limit value.

  Further, the limit value can be calculated based on the transmission rate associated with the domain name of the data transmitting apparatus that has transmitted the communication packet stored in the priority packet holding unit.

  Therefore, in a communication network that transmits a plurality of data flows at the same time, it is possible to preferentially transmit a data flow for which QoS is to be secured according to the domain name of the data transmitting apparatus that transmits the data flow. .

  Furthermore, in the communication control device according to the present invention, the second storage unit includes a data flow that is not a target to be transmitted preferentially together with a domain name of the data transmission device that transmits a data flow that is a target to be transmitted preferentially. Stores the domain name of the data transmission device to be transmitted, and further associates with the domain name whether the data flow transmitted by the data transmission device having the domain name needs to be transmitted with priority. The priority storage information is stored, and the first storage unit is associated with the communication address of the data transmission device associated with the communication address of the data reception device, and further includes the priority necessity information. The priority necessity information associated with the domain name of the data transmitting device extracted by the domain name / address extracting means is A first priority necessity information acquisition unit that acquires from the second storage unit, wherein the transmission control information generation unit includes the communication address of the data transmission device acquired by the address acquisition unit and the domain name / address extraction unit; The communication address of the data receiving device extracted by the client, the domain name of the data transmitting device extracted by the domain name / address extracting unit, and the priority necessity information acquired by the first priority necessity information acquiring unit. The data flow transmission control means is further associated with the communication address of the transmission source extracted by the transmission source address / destination address extraction means. The second priority necessity information acquisition means for acquiring the priority necessity information from the first storage unit is acquired by the second priority necessity information acquisition means. When the priority necessity information indicates that the data flow does not need to be transmitted with priority, the data flow transmitted from the data transmission device to the data reception device is reduced in priority. It is good also as a structure which transmits to a 1st communication network.

  According to the above configuration, the priority necessity information associated with the domain name of the data transmission device extracted by the domain name / address extraction unit can be acquired from the second storage unit. Further, the communication address of the data transmission device acquired by the address acquisition unit, the communication address of the data reception device extracted by the domain name / address extraction unit, the domain name of the data transmission device extracted by the domain name / address extraction unit, The priority necessity information acquired by the first priority necessity information acquisition unit can be associated with and stored in the first storage unit. Then, priority necessity information associated with the communication address of the transmission source extracted by the transmission source address / destination address extraction unit can be acquired from the first storage unit. When the priority necessity information acquired by the second priority necessity information acquisition unit indicates that the data flow does not need to be transmitted preferentially, the data flow transmitted from the data transmission device to the data reception device Can be transmitted to the first communication network at a lower priority.

  Therefore, when transmitting the data flow transmitted from the data transmission device to the first communication network, the priority necessity information stored in the second storage unit in association with the domain name of the data transmission device is the data transmission When the data flow transmitted by the apparatus indicates that the data flow is not a target to be transmitted with priority, the data flow transmitted from the data transmitting apparatus can be controlled to be transmitted with a reduced priority. In other words, the priority necessity information stored in the second storage unit in association with the domain name of the data transmission device indicates that the data flow transmitted by the data transmission device needs to be transmitted with priority. When the data flow is transmitted, the data flow transmitted from the data transmission device is transmitted to the first communication network without lowering the priority of the data flow. As a result, the data flow can be transmitted to the first communication network with higher priority than the data flow transmitted with a lower priority.

  Therefore, according to the present invention, the priority of the data flow transmitted from the data transmitting apparatus having each domain name is not lowered according to the priority necessity information associated with the domain name stored in the second storage unit. It is possible to transmit to the network or to transmit with lower priority.

  Furthermore, the communication control apparatus according to the present invention presents a user interface that can be input in association with the domain name of the data transmitting apparatus and the priority necessity information to the data receiving apparatus, and is input through the user interface. The information processing apparatus may further include a priority necessity information setting unit that associates the domain name of the data transmission device with the priority necessity information and stores the information in the second storage unit.

  According to the above configuration, the data transmission device that presents the user interface that can be input in association with the domain name of the data transmission device and the priority necessity information to the data reception device, and is input through the user interface The domain name and the priority necessity information can be associated with each other and stored in the second storage unit.

  Therefore, the user can input the domain name of the data transmission apparatus and the priority necessity information in association with each other. That is, the user can specify whether to transmit each data flow without lowering the priority or with lower priority.

  Therefore, it is possible to set a data flow that should ensure QoS according to the user's intention.

  Furthermore, the communication control apparatus according to the present invention can control the transmission amount of the communication packet by the data transmission apparatus in the data flow that is a target to be transmitted to the first communication network with a lower priority. The data transmission device may be configured to transmit to the data reception device using a communication protocol.

  According to the above configuration, the data flow that is the target to be transmitted to the first communication network with a lower priority is further transmitted by the communication protocol that controls the transmission amount of the communication packet by the data transmission device.

  Therefore, if the priority of a data flow that is not a target to be preferentially transmitted is reduced and transmitted to the first communication network, the amount of communication packets of the data flow is reduced, so that the amount of the response is also reduced. By controlling the communication protocol, the communication packet amount of the data flow transmitted from the data transmission device to the second communication network is reduced. For this reason, in the second communication network, the transmission band (transmission rate) used by the data flow that is not the target of transmission is reduced, so that a free transmission band can be provided in the second communication network. In other words, even when the data flow to be preferentially transmitted and the data flow not to be preferentially transmitted are transmitted at the same time on the second communication network, the data flow is preferentially transmitted on the second communication network. The data flow that is not the target of preferential transmission does not occupy all the transmission bands other than the transmission band used by the data flow to be performed.

  Therefore, even if the transmission rate of the data flow to be preferentially transmitted increases momentarily (temporarily), the transmission rate of the data flow to be preferentially transmitted and the transmission rate of the data flow not to be preferentially transmitted It is possible to increase the probability that the sum of the above will not exceed the line capacity of the second communication network. When the line capacity of the second communication network is smaller than the line capacity of the first communication network, the probability that the line capacity of all the communication networks on the communication path is not exceeded can be increased.

  Therefore, in the second communication network and the first communication network, it is possible to suppress transmission delay and jitter of a data flow that is transmitted preferentially. There is an effect that it is possible to suppress disturbance in the reproduction of video and audio in the data flow.

  The communication control device may be realized by a computer. In this case, a control program for the communication control device for causing the communication control device to be realized by the computer by causing the computer to operate as each of the means, and A computer-readable recording medium on which it is recorded also falls within the scope of the present invention.

  As described above, the communication control device according to the present invention includes the first storage unit that stores the communication address of the data transmission device and the communication address of the data reception device in association with each other, and the above-described data flow. Source address / destination address extraction means for extracting the source communication address and destination communication address from the communication packet, and the source communication extracted by the source address / destination address extraction means When the pair of the address and the communication address of the transmission destination is not stored in the first storage unit, the data flow transmitted from the data transmission device to the data reception device is reduced in priority to the first data flow. Data flow transmission control means for transmitting to the communication network.

  Further, the control method of the communication control apparatus according to the present invention includes a source address / destination address extraction step for extracting the source communication address and the destination communication address from the communication packet constituting the data flow. And the transmission source address / destination address extraction step, the data transmission is performed when the pair of the transmission source communication address and the transmission destination communication address is not stored in the first storage unit. A data flow transmission control step in which the data flow transmitted from the device to the data receiving device is transmitted to the first communication network at a reduced priority.

  Therefore, when transmitting the data flow transmitted from the data transmission device to the first communication network, the combination of the communication address of the transmission source and the communication address of the transmission destination of the communication packet constituting the data flow is the first storage unit. If the data flow is not stored, the data flow can be controlled to be transmitted with a lower priority. In other words, when a combination of a communication address of a transmission packet and a communication address of a transmission destination of communication packets constituting the data flow is stored in the first storage unit, the data flow is transferred to the first communication network. When transmitting, the data flow is transmitted without lowering the priority. As a result, the data flow can be transmitted to the first communication network with higher priority than the data flow transmitted with a lower priority.

  Therefore, according to the present invention, it is possible to preferentially transmit a data flow that is a target for securing QoS in a communication network that transmits a plurality of data flows simultaneously. For example, in a communication network that simultaneously transmits a video data flow and an FTP data flow, a video data flow that is easily affected by transmission delay, jitter, and the like is transmitted preferentially over an FTP data flow. Since it is possible to suppress the occurrence of transmission delay, jitter, and the like, it is possible to suppress the occurrence of disturbance in the reproduction of video and audio in the data receiving apparatus that receives the video data flow. That is, there is an effect that QoS of a real-time data flow such as a video data flow can be secured.

It is a block diagram which shows schematic structure of the communication control apparatus (HGW) which concerns on one Embodiment of this invention. 1 is a block diagram schematically showing a basic configuration example of a communication control system including a communication control device according to the present invention. It is a block diagram which shows typically an example of the specific structure of the communication control system shown in FIG. An example of how the transmission rate of the data flow in the access network decreases as a result of limiting the transmission rate when the data flow is sent to the home network in the communication control device (HGW) shown in FIG. It is a schematic diagram shown. FIG. 4 is a sequence diagram schematically illustrating an example of a state in which transmission of a data flow is controlled by a communication control device (HGW) in the communication control system illustrated in FIG. 3. It is a flowchart which shows the outline | summary of the flow of a process when the communication control apparatus (HGW) shown in FIG. 1 receives a packet. 3 is a flowchart showing an outline of a flow of queue assignment information generation processing in the communication control apparatus (HGW) shown in FIG. 1. 3 is a flowchart showing an outline of a flow of a transmission rate control process in the communication control apparatus (HGW) shown in FIG. 1. It is a schematic diagram which shows the example of a screen of the simple version QoS object setting screen which the communication control apparatus (HGW) shown in FIG. 1 and FIG. 12 provides. It is a schematic diagram which shows the example of a screen of the detailed version QoS object setting screen which the communication control apparatus (HGW) shown in FIG. 1 provides. It is a schematic diagram which shows an example of the time transition of the transmission band used in an access network when the transmission rate of a data flow is restrict | limited by the communication control apparatus (HGW) shown in FIG. It is a block diagram which shows schematic structure of the communication control apparatus (HGW) which concerns on other one Embodiment of this invention. FIG. 13 is a schematic diagram illustrating a screen example of a QoS target setting screen provided by the communication control device (HGW) illustrated in FIG. 12. It is a schematic diagram which shows an example of the time transition of the transmission band used in an access network when the transmission rate of a data flow is restrict | limited by the communication control apparatus (HGW) shown in FIG. FIG. 15A is a diagram illustrating an example of temporal transition of a transmission band used by each data flow when two types of data flows are transmitted on the access network in the related art. FIG. 15B is a diagram illustrating an example of a state in which two types of data flows are transmitted on a communication network having a larger line capacity than the access network according to the related art.

  In this specification, “packet” refers to a communication packet transmitted in a communication network.

  In this specification, “data flow” refers to one or a plurality of packets belonging to a series of data that need to be transmitted continuously. A series of data that needs to be transmitted continuously is, for example, a meaningful group of data such as one video content or one audio content. Therefore, to give an example, a group of packets when a single video content file held in the server device is transmitted to the receiving device as a plurality of continuous packets is a data flow.

  The data flow of video content and the data flow of FTP are also referred to as “video data flow” and “FTP data flow”, respectively. A packet belonging to the video data flow is also referred to as “video data packet”, and a packet belonging to the FTP data flow is also referred to as “FTP data packet”.

  Further, in this specification, “real-time data flow” refers to a data flow that needs to be transmitted in real time by streaming transmission of video and audio. Further, “non-real time data flow” refers to a data flow that does not need to be transmitted in real time, such as data transfer by FTP.

  A data flow that needs to be transmitted with priority is also referred to as a “priority data flow”. A real-time data flow is usually a priority data flow because it needs to be transmitted in real time by streaming transmission. However, even in the case of a real-time data flow, the user can specify that it is not necessary to preferentially transmit. A data flow that does not need to be transmitted with priority is also referred to as a “non-priority data flow”. A non-real time data flow is usually a non-priority data flow because it does not need to be transmitted in real time.

  In addition, the fact that it is necessary to perform transmission preferentially is also referred to as “a QoS target”. Further, it is also referred to as “not subject to securing QoS” that there is no need to transmit preferentially.

(Basic configuration of communication control system)
A basic configuration of a communication control system including a communication control apparatus according to each embodiment will be described with reference to FIG. FIG. 2 is a block diagram schematically illustrating a basic configuration example of a communication control system 900 including the communication control apparatus according to each embodiment. As illustrated, the communication control system 900 includes at least a communication control device 100, one or more servers (data transmission devices) 600, and one or more data transmission / reception devices (data reception devices) 400. .

  As shown in the figure, the communication control device 100 is communicably connected to the first communication network 500 and the second communication network 700. The server 600 is connected to the second communication network 700 so as to be communicable. The data transmitting / receiving apparatus 400 is communicably connected to the first communication network 500.

  The communication control device 100 is a device that controls the transmission of packets exchanged between the server 600 and the data transmission / reception device 400 to realize QoS. A typical example of the communication control apparatus 100 is an HGW (Home Gateway). In this case, the first communication network 500 is a home network such as a LAN constructed in the user's house, for example. The second communication network 700 is, for example, a communication network constructed outside the user's home (that is, the Internet and an access network). Note that each of the first communication network 500 and the second communication network 700 may be a single communication network or a plurality of communication networks.

  The data transmission / reception device 400 is a terminal that transmits and receives various data such as video content, data transferred by FTP, VoIP data, and the like, specifically, an STB, a PC (Personal Computer), and the like. Other examples include a TV (which can be connected to a communication network), a hard disk recorder (which can be connected to a communication network), a VoIP adapter which is a device that converts an IP packet into an analog telephone signal, and the like. Finally, IP telephones that are telephones with built-in VoIP adapter functions, IP cameras that are devices that transmit video data and audio data as IP packets, NAS (Network Attached Storage) that is a network accessible hard disk, etc. The data transmitting / receiving apparatus 400 may include a terminal that receives (or transmits) data.

  The server 600 is a server device that provides various types of content, such as a video distribution server that provides video content, an FTP server that can transfer data by FTP, a DNS (Domain Name System) server, and the like.

  In the above configuration, when the server 600 transmits a data flow to the data transmission / reception device 400 in response to a request from the data transmission / reception device 400, the communication control device 100 existing on the path transmits the data flow to the data transmission / reception device 400. 2 is transmitted from the communication network 700 to the first communication network 500.

  At this time, the communication control apparatus 100 determines whether or not the data flow is a target for limiting the transmission rate according to the domain name of the server 600 that is the transmission source of the data flow, and the target for limiting the transmission rate. In this case, the outline of the present invention is to limit the transmission rate when sending packets belonging to the data flow to the first communication network 500 to a predetermined limit value or less.

  Hereinafter, the present invention will be described using a specific configuration example of the communication control system 900 shown in FIG.

(Specific configuration example of communication control system)
A specific configuration example of the communication control system 900 illustrated in FIG. 2 will be described with reference to FIG. FIG. 3 is a block diagram schematically showing an example of a specific configuration of the communication control system 900 shown in FIG. In FIG. 3, a specific example is applied to each device and communication network shown in FIG.

  First, the home network 501 corresponds to the first communication network 500 shown in FIG. The home network 501 is assumed to be a LAN configured by Ethernet (registered trademark) (hereinafter simply referred to as Ethernet).

  Next, the Internet 701, the access network 702, and the base station 703 correspond to the second communication network 700 shown in FIG. The access network 702 is assumed to be FTTH (Fiber To The Home). The base station 703 is assumed to be a service provider router or the like, and connects the access network 702 and the Internet 701.

  The line capacity of the access network 702 is often smaller than the Internet 701 and the home network 501 as is generally known. Here, it is assumed that the line capacity of the Internet 701 and the home network 501 is 100 Mbps or more, and the line capacity of the access network 702 is 70 Mbps.

  Next, the STB 401, STB 402, STB 403, and PC 404 correspond to the data transmission / reception apparatus 400 shown in FIG. Each of STB 401, STB 402, and STB 403 is communicably connected to television 405, television 406, and television 407 via an AV cable such as HDMI (High Definition Multimedia Interface) in order to display received video. ing.

  Note that the IP addresses (communication addresses) of the STB 401, STB 402, STB 403, and PC 404 are “192.168.0.1”, “192.168.0.2”, “192.168.0.3”, and “192.168.0.4”, respectively. .

  Next, the DNS server 601, the video distribution server 602, the video distribution server 603, the video distribution server 604, the FTP server 605, and the update server 606 correspond to the server 600 illustrated in FIG.

  The DNS server 601 is a general DNS server. That is, for each domain name, a corresponding IP address is managed, and a message that inquires an IP address of a device to be queried from an external device, and that includes the domain name of the device to be queried (hereinafter referred to as “message”) , DNS inquiry message (first request)). Then, a response message including the IP address corresponding to the domain name of the device to be queried included in the received DNS inquiry message is returned to the DNS inquiry message transmission source (that is, name resolution can be performed). Hereinafter, the response message is referred to as a DNS response message.

  Next, the video distribution server 602, the video distribution server 603, and the video distribution server 604 are general video distribution servers that provide video content as streaming data. Note that service contents provided by the video distribution server 602, the video distribution server 603, and the video distribution server 604 (for example, the format of the video to be distributed and the communication protocol for transmitting the video) are different. The service provided by the video distribution server 602 is referred to as “video distribution service A”, the service provided by the video distribution server 603 is referred to as “video distribution service B”, and the video distribution server 604 provides the service. The service is referred to as “video distribution service C”.

  Next, the FTP server 605 is a general FTP server capable of transferring data by FTP.

  Next, the update server 606 is assumed to be a data server operated by a distributor of the HGW 101 (communication control device) or the like, and update information and update programs for data stored in the QoS target storage unit 22 (described later) of the HGW 101. Is a server that provides the HGW 101 with a predetermined communication protocol. For this purpose, the update server 606 stores data (a combination of a service name, a domain name, and a necessary transmission rate) constituting an entry of the QoS target storage unit 22 in a state where it can be provided to the outside. It is assumed that the administrator of the update server 606 stores the data in the update server 606. Further, the domain name stored in the update server 606 may be described by a general regular expression. The use of regular expressions will be described later.

  The IP addresses of the video distribution server 602, the video distribution server 603, the video distribution server 604, and the FTP server 605 are “101.101.101.1”, “102.102.102.1”, “103.103.103.1”, and “201.201. 201.1 ". The domain names of the video distribution server 602, the video distribution server 603, the video distribution server 604, and the FTP server 605 are “sv1.vod.service-a.co.jp” and “vod1.service-b.co”, respectively. .jp "," service-c.co.jp ", and" ftp.co.jp ".

  Finally, the HGW 101 corresponds to the communication control apparatus 100 shown in FIG. In addition, it is assumed that the HGW 101 further has a general DNS server function, and the STB 401, STB 402, STB 403, and PC 404 recognize the HGW 101 as a default DNS server.

  In the above configuration, for example, when the user views the video content of the video distribution service A on the television 405, the STB 401 receives the video data flow from the video distribution server 602 via the HGW 101 and receives the video data flow. The video data flow is output to the television 405. When another user downloads data by FTP on the PC 404, the PC 404 receives the FTP data flow from the FTP server 605 via the HGW 101, and stores the received FTP data flow in its own device. To do.

  Note that the STB 401, STB 402, and STB 403, when accessing any of the video distribution server 602, the video distribution server 603, and the video distribution server 604, query the DNS server 601 for the IP address of the access destination via the HGW 101. Shall be performed. Similarly, when accessing the FTP server 605, the PC 404 makes an inquiry about the IP address of the FTP server 605 to the DNS server 601 via the HGW 101.

  In the following description, the term “data transmission / reception device 400” is a generic term for STB 401, STB 402, STB 403, and PC 404 unless otherwise specified. In addition, the term “server 600” is a generic term for the DNS server 601, the video distribution server 602, the video distribution server 603, the video distribution server 604, the FTP server 605, and the update server 606 unless otherwise specified. It shall be.

(Outline of the present invention)
A feature of the present invention is whether or not the data flow flowing from the access network 702 toward the home network 501 needs to be preferentially transmitted by the HGW 101 (that is, whether or not QoS is to be secured). If it is determined that there is no need to preferentially transmit, when the data flow is transmitted from the HGW 101 to the home network 501, the priority is lowered.

  Further, a further feature of the present invention is to determine whether or not it is necessary to preferentially transmit a data flow according to the domain name of the server 600 that transmits the data flow. Specifically, when the domain name of the server 600 that has transmitted the data flow flowing from the access network 702 to the home network 501 is different from the domain name stored in advance in the HGW 101, the data flow is transmitted from the HGW 101 to the home network 501. When sending, the priority is lowered.

  Here, “sending the priority lower and sending” specifically restricts the transmission rate of the data flow to be equal to or lower than the limit value. For example, when a data flow is transmitted from the access network 702 to the HGW 101 at 30 Mbps, when the data flow is transmitted to the home network 501, the data flow is limited to 20 Mbps or less. Hereinafter, the limit value is also referred to as “rate limit value LR”. A method for calculating the rate limit value LR will be described later.

  For example, a case where only the domain name of the video distribution server 602 is stored in the HGW 101 as the domain name of the server 600 that provides a service that is specified in advance by a user operation or the like as a target for securing QoS. To In this case, when the HGW 101 receives the packet of the FTP data flow transmitted from the FTP server 605, the domain name of the FTP server 605 is different from the domain name stored in advance in its own device. The transmission rate at the time of transmission to the home network 501 is limited to be equal to or less than the rate limit value LR. On the other hand, when a video data flow packet transmitted from the video distribution server 602 is received, the domain name of the video distribution server 602 matches the domain name stored in advance in the own device. Are sent to the home network 501 without restriction.

  Furthermore, even if the domain name of the server 600 that has transmitted the data flow flowing from the access network 702 to the home network 501 matches the domain name stored in advance in its own device, it is not a target for securing QoS. If there is no service (that is, there is no need to perform transmission preferentially) by a user operation or the like, the transmission rate when sending the data flow to the home network 501 is equal to or less than the rate limit value LR. You may restrict | limit so that it may become.

  For example, a case where the domain name of the video distribution server 603 is stored in the HGW 101 as an example of the domain name of the server 600 that provides a service specified in advance by a user's operation or the like that is not a QoS reservation target will be described. . In this case, when the HGW 101 receives the packet of the video data flow transmitted from the video distribution server 603, the domain name of the video distribution server 603 matches the domain name stored in advance in its own device, but the received packet Is transmitted to the home network 501 so that the transmission rate is less than or equal to the rate limit value LR. This is because although the domain name of the video distribution server 603 is stored in its own apparatus, it is a service designated by the user's operation or the like that it is not a target for securing QoS.

  In this way, when the transmission rate when the data flow is transmitted to the home network 501 is limited in the HGW 101, the transmission rate of the data flow in the access network 702 can be suppressed as a result (about this). Will be described later). When this is applied to a non-priority data flow, the HGW 101 limits the transmission rate when sending the non-priority data flow to the home network 501, resulting in an access network for the non-priority data flow. The transmission rate at 702 can be suppressed.

  As a result, even if the priority data flow and the non-priority data flow are transmitted at the same time in the access network 702, all the transmission bands other than the transmission band used by the priority data flow in the access network 702 Are not occupied by non-priority data flows. That is, “free” can be provided in the transmission band in the access network 702.

  Therefore, even if the transmission rate of the priority data flow increases momentarily (temporarily), the sum of the transmission rate of the priority data flow and the transmission rate of the non-priority data flow exceeds the line capacity of the access network 702. Can increase the probability of not. Since the access network 702 has the smallest line capacity on the communication path between the server 600 and the data transmission / reception device 400, the total of the transmission rate of the priority data flow and the transmission rate of the non-priority data flow is equal to that of the access network 702. If the line capacity is not exceeded, as a result, the line capacity of all the communication networks on the communication path is not exceeded.

  Therefore, according to the present invention, transmission delay and jitter of the priority data flow can be suppressed in all communication networks on the communication path between the server 600 and the data transmission / reception device 400. Thus, there is an effect that it is possible to suppress the disturbance of the reproduction of video and audio in the real-time data flow which is the priority data flow.

  The HGW 101 temporarily buffers one or a plurality of packets in order to send a packet for limiting the transmission rate and a packet for which the transmission rate is not limited to the home network 501, and the buffering. There are two FIFO (First In First Out) queues that sequentially transmit the received packets to the home network 501. One is a queue (rate non-limitation queue (priority packet holding unit) 143 described later) used for sending packets to the home network 501 without limiting the transmission rate, and the other is a transmission rate. Is a queue (rate limiting queue 144, which will be described later) used to send packets to the home network 501 while limiting the value to be equal to or less than the rate limiting value LR.

(Reason why the transmission rate in the access network can be reduced by limiting the transmission rate of packets sent to the home network)
Here, as described above, the reason why “the transmission rate at the time of sending the data flow to the home network 501 is limited can consequently reduce the transmission rate of the data flow in the access network 702”. To do.

  First, if the transmission rate at the time of sending the data flow to the home network 501 is limited, the amount of packets received by the data transmitting / receiving apparatus 400 decreases. In response to this, the amount of ACK (acknowledge) packets that the data transmitting / receiving apparatus 400 returns to the server 600 as a response to the received packet is also reduced.

  On the other hand, it is assumed that generally known window control is performed in server 600 in order to control the amount of packets transmitted from the server device in accordance with the reception status of the data receiving device. For this reason, when the amount of ACK packets returned from the data transmitting / receiving device 400 decreases, control is performed to suppress the amount of subsequent packets transmitted to the data transmitting / receiving device 400 accordingly. As a result, the amount of packets transmitted on the access network 702 decreases, and as a result, the data flow transmission rate decreases.

  Here, with reference to FIG. 4, when the transmission rate at the time when the data flow is transmitted to the home network 501 by the HGW 101 is limited, the state in which the transmission rate of the data flow in the access network 702 is reduced as a result will be described. To do. FIG. 4 is a schematic diagram showing an example of how the transmission rate of the data flow in the access network 702 decreases as a result when the transmission rate when the data flow is sent to the home network 501 by the HGW 101 is limited. is there.

  As shown in FIG. 4, between time T11 and time T16, the FTP server 605 sequentially transmits FTP data flows to the HGW 101 via the access network 702, and the HGW 101 further sends the FTP to the PC 404 via the home network 501. The data flow is transmitted sequentially.

  It is assumed that the HGW 101 does not limit the transmission rate of the FTP data flow from time T11 to time T13 and limits the transmission rate of the FTP data flow from time T13 to time T16. In addition, as a trigger to start limiting the transmission rate of the FTP data flow, for example, the HGW 101 starts to receive the video data flow transmitted from the video distribution server 602 via the access network 702, etc. Is mentioned. In this case, in order to preferentially transmit the video data flow, the transmission rate limitation of the FTP data flow is started.

  First, the flow of FTP data packets belonging to the FTP data flow from time T11 to time T12 will be described.

  As shown in the figure, it is assumed that the FTP server 605 transmits three FTP data packets F1, F2, and F3 to the PC 404. It is assumed that the FTP server 605 knows that the PC 404 can buffer up to three FTP data packets by prior negotiation with the PC 404 (in practice, more than three). However, for simplicity of explanation, the number of packets is three here). Then, the HGW 101 that has received the FTP data packets F1, F2, and F3 sends these FTP data packets to the home network 501 without limiting the transmission rate. When the PC 404 receives these FTP data packets, it returns an ACK packet for each FTP data packet to the FTP server 605.

  Subsequently, since the FTP server 605 has received all the ACK packets for the FTP data packets F1, F2, and F3, the subsequent three FTP data packets F4, F5, and F6 are directed to the PC 404 from time T12 to time T13. To send. The HGW 101 that has received the FTP data packets F4, F5, and F6 transmits these FTP data packets to the home network 501 without limiting the transmission rate. When the PC 404 receives these FTP data packets, it returns an ACK packet for each FTP data packet to the FTP server 605.

  Subsequently, since the FTP server 605 has received all the ACK packets for the FTP data packets F4, F5, and F6, the subsequent three FTP data packets F7, F8, and F9 are directed to the PC 404 from time T13 to time T14. To send.

  Here, the HGW 101 limits the transmission rate of the FTP data flow from time T13. For example, it is assumed that only one FTP data packet is sent to the home network 501 per unit time. In this case, the HGW 101 that has received the FTP data packets F7, F8, and F9 does not transmit all these FTP data packets to the PC 404, and at this time, sends only the FTP data packet F7 to the home network 501 as shown in the figure. The FTP data packets F8 and F9 are buffered in the own apparatus. When the PC 404 receives the FTP data packet F7, it returns an ACK packet for the FTP data packet F7 to the FTP server 605.

  Subsequently, since the FTP server 605 has received only the ACK packet for the FTP data packet F7, from time T14 to time T15, only the next new FTP data packet F10 is transmitted to the PC 404. That is, the amount of FTP data packets flowing through the access network 702 decreases from three to one, and as a result, the transmission rate of the FTP data data flow in the access network 702 decreases.

  Since the HGW 101 continues to limit the transmission rate of the FTP data flow, the FTP data packet F10 is buffered in its own device, and the already buffered FTP data packet F8 is sent to the home network 501. When the PC 404 receives the FTP data packet F8, it returns an ACK packet for the FTP data packet F8 to the FTP server 605.

  Similarly, from time T15 to time T16, the FTP server 605 transmits only one subsequent new FTP data packet F11 to the PC 404. The HGW 101 buffers the FTP data packet F11 in its own device, and sends the already buffered FTP data packet F9 to the home network 501.

  As described above, if the transmission rate when the data flow is sent to the home network 501 is limited in the HGW 101, as a result, the transmission rate of the data flow in the access network 702 can be reduced.

  As described above, since the server 600 expects the transmission rate in the access network 702 to decrease by performing window control based on the ACK packet, the transmission rate is limited by the HGW 101. It is desirable that the target data flow is exchanged by a communication protocol having a window control function (for example, TCP (Transmission Control Protocol)). That is, the HGW 101 is desirably a device that can control transmission of a data flow transmitted by a communication protocol having a window control function.

(Calculation method of rate limit value LR)
When the line capacity of the access network 702 is abbreviated as “AC” and the total transmission rate necessary for transmission of the priority data flow is abbreviated as “DC”, the HGW 101 transmits the non-priority data flow according to the following equation. It is assumed that the rate limit value LR is calculated.

LR = AC-DC
Here, the value of AC can be obtained, for example, by the following two methods. That is, (1) the HGW 101 may obtain from the base station 703 in the connection process with the access network 702, or (2) the user may measure using a speed measurement site or the like and register in advance in the HGW 101. It is done.

  Next, it is assumed that the value of DC is obtained by one of the following two methods.

  The first method is a method in which a user registers a priority data flow in a QoS target storage unit 22 described later in advance. Then, the HGW 101 obtains a transmission rate necessary for transmission of the registered priority data flow with reference to the QoS target storage unit 22. It is assumed that which data flow is preferentially transmitted is set in the HGW 101 in advance at the time of factory shipment or the like, and the HGW 101 operates even if the user does not perform a registration operation.

  Also, the HGW 101 may detect how many data flows are transmitted, or the user may specify the number for each data flow. Further, instead of allowing the user to specify the number of data flows, the number of data transmitting / receiving apparatuses 400 that receive the data flows may be specified. When the user specifies the number for each data flow, the HGW 101 may always ensure the transmission rate for the number specified for each data flow. Also, the number of transmissions for each service may be fixed, and the HGW 101 may always ensure a transmission rate for the number of transmissions fixed for each service. For example, the transmission rate is calculated on the assumption that one data flow is transmitted for each service.

  The second method is a method in which the user registers the total value of the transmission rate of the priority data flow in the HGW 101 in advance. The above total value may be obtained by checking the user's manual or service provider's website for each service, calculating the transmission rate required for the service scheduled to be received, and registering it in the HGW 101. Further, instead of the total value of the transmission rates of the priority data flows, the total value of the transmission rates of the non-priority data flows may be registered.

  As described above, there are a plurality of methods for obtaining the AC value and the method for obtaining the DC value, but any combination thereof may be used.

  For example, with respect to the AC value, the HGW 101 obtains the priority data flow from the base station 703 in the process of connecting to the base station 703 via the access network 702, and the DC value is assigned to the HGW 101 by the user. You may combine with the method of registering beforehand. Hereinafter, this combination is referred to as “combination A”.

  Further, the AC value is measured by a user using a speed measurement site and registered in advance in the HGW 101, and the DC value is the total transmission rate of the priority data flow. May be combined with a method of registering in advance. Hereinafter, this combination is referred to as “combination B”. In the case of the combination B, the rate limit value LR can be calculated in advance from a previously registered AC value and DC value.

(Overview of controlling data flow transmission with HGW)
With reference to FIG. 5, how the HGW 101 controls data flow transmission in the communication control system 900 shown in FIG. 3 will be described. FIG. 5 is a sequence diagram schematically showing an example of a state in which the HGW 101 controls data flow transmission in the communication control system 900 shown in FIG.

  First, a flow of a user receiving (downloading) data provided by the FTP server 605 using the PC 404 (denoted as a sequence P1 in FIG. 5) will be described.

  When a user operation for obtaining data provided by the FTP server 605 is performed on the PC 404 (for example, an operation for downloading predetermined data by executing Web browser software), the PC 404 receives FTP data. As a process to start (reception start process), a DNS inquiry message for inquiring the IP address (communication address) of the FTP server 605 is transmitted to the default DNS server (here, the HGW 101) (step S201).

  Note that the reception start process may be performed using a generally known method. For example, it is assumed that FTP client software is running on the PC 404 and that the user can select one or more download targets.

  When the user selects a download target, URIs (Uniform Resource Identifiers) associated with the download target are specified. Here, for example, a URI “ftp://ftp.co.jp/downloaddata001” is specified. Then, the PC 404 acquires a domain name from the identified URI. In the above example, the domain name “ftp.co.jp” is acquired. Then, a DNS inquiry message for inquiring about the IP address corresponding to the acquired domain name is transmitted to the default DNS server. This DNS inquiry message includes the acquired domain name.

  The destination to which the DNS inquiry message is transmitted is the default DNS server (HGW 101), but the IP address of the default DNS server can be set in advance in the PC 404 by a keyboard operation or the like, for example, or by DHCP (Dynamic Although it is conceivable that the PC 404 obtains in advance using a general technique such as Host Configuration Protocol), it is not an essential part of the present invention, so the description thereof is omitted here.

  Next, a process when the HGW 101 receives a DNS inquiry message from the PC 404 will be described. Here, it is assumed that the HGW 101 does not directly manage the IP address corresponding to the domain name included in the received DNS inquiry message. In this case, the HGW 101 further transmits a DNS inquiry message including the domain name to the DNS server 601 (step S202). The DNS server 601 is, for example, a DNS server provided by a service provider, and the IP address of the DNS server 601 is registered in advance in the HGW 101 by the user, or is acquired in advance by the HGW 101 using DHCP. In general, name resolution is performed recursively via a plurality of DNS servers. However, in order to omit the description here, if the HGW 101 makes an inquiry to the DNS server 601, the IP of the FTP server 605 is used. A description will be given assuming that an address can be acquired. In general, a service provider constructs a DNS server and manages the IP address of the server provided by the service provider. Here, the DNS server 601 manages the IP addresses of all servers. To do.

  Next, a process when the DNS server 601 receives a DNS inquiry message from the HGW 101 will be described. The DNS server 601 stores an IP address corresponding to each domain name, and transmits an appropriate DNS response message in response to the DNS inquiry message. Accordingly, the DNS server 601 returns a DNS response message including “201.201.201.1”, which is an IP address corresponding to the domain name of the FTP server 605 “ftp.co.jp”, to the HGW 101 (step S203).

  When the HGW 101 receives the DNS response message, the HGW 101 transfers the DNS response message to the PC 404 that is an inquiry source. The PC 404 that has received this can know that the IP address corresponding to the domain name “ftp.co.jp” is “201.201.201.1”, and requests the FTP server 605 to download data. It becomes possible.

  The HGW 101 indicates whether the packet is stored in the rate non-limit queue 143 or the rate limit queue 144 in order to control transmission of a packet to be transferred later by the HGW 101 after returning the DNS response message to the PC 404. A process for generating information (hereinafter, queue allocation information) (hereinafter, queue allocation information generating process) is performed (step S204).

  Here, an overview of the queue assignment information generation process will be described. In the queue allocation information generation process, packets transmitted from the domain name server included in the DNS response message to the data transmission / reception device 400 that is the destination of the DNS response message are sent to the rate non-limit queue 143 and the rate limit queue 144 This is processing for generating queue allocation information indicating where to store and storing it in a queue allocation information storage unit 23 to be described later.

  Here, the queue allocation information preferentially transmits (1) one or a plurality of data indicating the domain name of the server 600, and (2) the domain name of the server 600 and the data flow transmitted from the server 600. Is generated based on either one or a plurality of data associated with information indicating whether or not (hereinafter also referred to as priority necessity information). The above (1) and (2) are also referred to as “QoS target data” below.

  The generation of the queue allocation information will be specifically described separately for the case where the QoS target data is (1) and the case (2).

  First, the case where the QoS target data is (1) will be described. In this case, if the domain name included in the DNS response message is not included in the QoS target data, a packet transmitted from the server of the domain name to the data transmitting / receiving apparatus 400 that is the destination of the DNS response message is Queue allocation information indicating that data is transmitted from the rate limiting queue 144 is generated. On the other hand, if the domain name included in the DNS response message is included in the QoS target data, a packet transmitted from the server having the domain name to the data transmitting / receiving apparatus 400 that is the destination of the DNS response message Queue assignment information indicating transmission from the unrestricted queue 143 is generated.

  Next, the case where the QoS target data is (2) will be described. In this case, if the domain name included in the DNS response message is included in the QoS target data, the priority necessity information stored in association with the domain name is further referred to, and the priority necessity information referred to is referred to. If the information indicates that the information is transmitted preferentially, a packet transmitted from the server having the domain name to the data transmitting / receiving apparatus 400 that is the destination of the DNS response message is sent from the rate non-limit queue 143. Queue assignment information indicating sending is generated.

  On the other hand, if the referenced priority information is information indicating “not preferentially transmitted”, a packet transmitted from the server having the domain name to the data transmitting / receiving apparatus 400 that is the transmission destination of the DNS response message. Is generated from the rate limiting queue 144.

  If the domain name included in the DNS response message is not included in the QoS target data, a packet transmitted from the server having the domain name to the data transmitting / receiving apparatus 400 that is the destination of the DNS response message Queue allocation information indicating transmission from the restriction queue 144 is generated.

  Here, the QoS target data will be described with a specific example. For example, when the data flow transmitted from the video distribution server 602 is a priority data flow (hereinafter also referred to as “QoS target”), the data indicating the domain name of the video distribution server 602 can be the QoS target data.

  Furthermore, data in which the domain name of the video distribution server 602 is associated with priority necessity information indicating that the data flow transmitted from the video distribution server 602 is preferentially transmitted can be the QoS target data.

  For example, when the data flow transmitted from the video distribution server 604 is a non-priority data flow (hereinafter also referred to as “not subject to QoS”), the domain name of the video distribution server 604 and the transmission from the video distribution server 604 are transmitted. Data associated with information indicating that the data flow to be transmitted is not preferentially transmitted can be QoS target data.

  In addition, regarding a data flow transmitted from a certain server 600, when it is not always necessary to preferentially transmit (it is not always a QoS target), the domain name of the server 600 is not included in the QoS target data. For example, the data flow transmitted from the FTP server 605 may always be a non-priority data flow (not always a QoS target), and therefore the domain name of the FTP server 605 is not included in the QoS target data. Therefore, when the domain name included in the DNS response message is not included in the QoS target data, the queue allocation information is not generated even if the queue allocation information generation process is executed. That is, the HGW 101 executes the queue assignment information generation process in step S204, but no queue assignment information is generated.

  Note that, in the transmission rate control process described later, according to the queue allocation information generated in the queue allocation information generation process, the server having the domain name included in the DNS response message sends the data transmission / reception apparatus 400 to which the DNS response message is transmitted. A packet belonging to the data flow transmitted to the destination is stored in either the rate non-limit queue 143 or the rate limit queue 144. When the domain name included in the DNS response message is not included in the queue assignment information, the server having the domain name included in the DNS response message is transmitted to the data transmission / reception apparatus 400 that is the destination of the DNS response message. Packets belonging to the data flow are stored in the rate limiting queue 144. Details of the transmission rate control processing will be described later.

  Returning to the description of the sequence diagram shown in FIG. After receiving the DNS response message, the PC 404 makes a request to download data to the FTP server 605 in order to start receiving FTP data (second request) (step S205). The FTP server 605 that receives the request from the PC 404 transmits an FTP data flow to the PC 404 as a response (step S206).

  When the HGW 101 on the path receives the FTP data flow, the HGW 101 performs a transmission rate control process, and stores the FTP data packet belonging to the received FTP data flow in the rate limiting queue 144 (step S207). Here, since the domain name of the FTP server 605 is not included in the queue assignment information generated in the queue assignment information generation process performed in step S204, the FTP data packet belonging to the received FTP data flow is rate-limited. Stored in the queue 144.

  On the other hand, at this time, there is no packet stored in the rate non-limit queue 143. Therefore, the FTP data packet stored in the rate limiting queue 144 is sent out without limiting the transmission rate (indicated as “normal transmission” in FIG. 5).

  Then, the PC 404 receives the FTP data packet transferred from the HGW 101, and stores the FTP data in its own apparatus (step S208).

  Next, while the PC 404 is receiving the FTP data flow, until a user different from the user of the PC 404 views the video content of the video distribution service A provided by the video distribution server 602 on the television 405. The flow (denoted as sequence P2 in FIG. 5) will be described.

  The user operates the STB 401 while viewing the screen of the television 405 connected to the STB 401, and performs a user operation for viewing the video content provided by the video distribution server 602. When the STB 401 accepts a user operation, the DNS inquiry for inquiring the IP address (communication address) of the video distribution server 602 to the default DNS server (HGW 101) as a process of starting reception of video content (reception start process). A message is transmitted (step S301). The process of starting the reception of the video content may be performed using a generally known method. For example, it is assumed that the STB 401 generates a menu screen on which thumbnails of one or more video contents to be downloaded are displayed, and displays the menu screen on the display unit. The data of this screen is described in, for example, HTML (HyperText Markup Language), and is provided from a portal server (not shown) different from the video distribution server 602. The STB 401 accesses the portal server via the Internet 701. The HTML is acquired (this communication sequence is not shown). Each thumbnail is associated with a URI indicating a storage location of data to be downloaded. Here, for example, a URI “http://sv1.vod.service-a.co.jp/content001” is specified. Then, the STB 401 acquires a domain name from the identified URI. In the above example, the domain name “sv1.vod.service-a.co.jp” is acquired. Then, a DNS inquiry message for inquiring about the IP address corresponding to the acquired domain name is transmitted to the default DNS server. This DNS inquiry message includes the acquired domain name.

  Subsequently, similar to the flow described in step S202, when the HGW 101 receives a DNS inquiry message from the STB 401, the HGW 101 transmits a DNS inquiry message including the domain name to the DNS server 601 (step S302).

  Subsequently, similar to the flow described in step S203, when the DNS server 601 receives the DNS inquiry message from the HGW 101, the DNS response message including “101.101.101.1” that is the IP address of the video distribution server 602, A reply is made to the HGW 101 (step S303). For example, the IP address of the default DNS server is set in the STB 401 by the user by operating the remote controller or the STB 401 automatically obtains it using DHCP or the like.

  When the HGW 101 receives the DNS response message, the HGW 101 transfers the DNS response message to the STB 401 that is an inquiry source. The STB 401 that has received this can know that the IP address of the video distribution server 602 is “101.101.101.1”, and can request video data from the video distribution server 602.

  After returning a DNS response message to the STB 401, the HGW 101 executes a queue assignment information generation process and attempts to generate queue assignment information (step S304).

  Here, when the video data flow transmitted from the video distribution server 602 is a priority data flow, the domain name of the video distribution server 602 and the video data flow transmitted from the video distribution server 602 are preferentially transmitted. Since the data associated with the priority necessity information shown is stored as the QoS target data, the packet transmitted from the video distribution server 602 to the STB 401 by the queue allocation information generation process is the rate unrestricted queue 143. Queue allocation information indicating that the message is to be sent out is generated.

  On the other hand, after receiving the DNS response message, the STB 401 makes a request for video data to the video distribution server 602 to start receiving video content (second request) (step S305). Note that the request procedure varies depending on the service and communication protocol, and may involve, for example, transmission / reception of a plurality of packets. However, since this is not an essential part of the invention, description thereof is omitted here.

  Then, the video distribution server 602 that has received the request from the STB 401 transmits a video data flow toward the STB 401 as a response (step S306).

  When the HGW 101 on the path receives the video data flow, the HGW 101 performs transmission rate control processing, and stores the video data packets belonging to the received video data flow in the rate unrestricted queue 143 (step S307). Here, since the domain name of the video distribution server 602 is included in the queue allocation information generated in the queue allocation information generation process performed in step S304, the video data packets belonging to the received video data flow are rate unrestricted. Stored in the queue 143. Therefore, the video data packet stored in the rate limiting queue 144 is sent without limiting the transmission rate (indicated as “normal transmission” in FIG. 5).

  The STB 401 receives the video data packet transferred from the HGW 101, converts (decodes) it into a video signal, and outputs it to the television 405, thereby reproducing the video (step S308).

  Next, the state of transmission of the FTP data flow (denoted as sequence P3 in FIG. 5) after transmission of the video data flow is started in sequence P2 will be described.

  It is assumed that the FTP data flow transmitted from the FTP server 605 to the PC 404 in step S206 is continuously transmitted. When the HGW 101 on the path receives the FTP data flow as in step S207, the HGW 101 performs transmission rate control processing, and stores the FTP data packet belonging to the received FTP data flow in the rate limiting queue 144 (step S207). S401).

  At this time, as described in step S307, there is a packet (that is, a video data packet) stored in the rate non-limit queue 143. Since the packet stored in the rate non-limit queue 143 needs to be transmitted with priority, the FTP data packet stored in the rate limit queue 144 is transmitted from the rate limit queue 144 with the transmission rate limited. (Referred to as “rate limited transmission” in FIG. 5).

  Then, the PC 404 receives the FTP data packet transferred from the HGW 101, and stores the FTP data in its own apparatus (step S402).

  By transmitting the FTP data packet and the video data packet in the above-described flow, the data provided by the FTP server 605 can be acquired by the PC 404, and the video distribution server 602 can be acquired by the television 405. The video content provided can be viewed. The FTP data packet is sent to the home network 501 without limiting the transmission rate by the HGW 101 when the video data packet is not transmitted, but is transmitted when the video data packet is transmitted. It is sent to the home network 501 while the rate is limited. As a result, the transmission rate of the FTP data packet in the access network 702 can be suppressed, and as a result, even when the video data flow and the FTP data flow are transmitted at the same time in the access network 702, Transmission delay and jitter of the video data flow can be suppressed.

  In FIG. 5, the sequence P1 and the sequence P2 are not executed overlapping in time, but the sequence P1 and the sequence P2 may be executed overlapping in time. In this case, the DNS inquiry message from the STB 401 and the DNS inquiry message from the PC 404 may arrive at the HGW 101 at the same time. In addition, the video data packet transmitted from the video distribution server 602 and the FTP data packet transmitted from the FTP server 605 may arrive at the same time. Even in such a case, each process is performed as described above, and the video data packet transmitted from the video distribution server 602 is stored in the rate unrestricted queue 143 of the HGW 101, whereas the FTP server The FTP data packet transmitted from 605 is stored in the rate limiting queue 144 of the HGW 101. Then, the HGW 101 preferentially sends out the packet in the rate non-limit queue 143.

[Embodiment 1]
An embodiment of the present invention will be described below with reference to FIGS. In the present embodiment, a description will be given of a mode in which the HGW 101 limits the transmission rate of the non-priority data flow based on the rate limit value LR calculated from the AC value and the DC value obtained by the method of the combination A described above. To do. Note that the HGW 101 according to the present embodiment is particularly referred to as an HGW 101a.

(Configuration of HGW)
Next, a schematic configuration of the HGW 101a as the communication control apparatus 100 will be described with reference to FIG. FIG. 1 is a block diagram showing a schematic configuration of the HGW 101a.

  As shown in FIG. 1, the HGW 101a includes a main control unit 10, a storage unit 20, a WAN (Wide Area Network) side communication unit 31, and a LAN side communication unit 32.

  The main control unit 10 controls the storage unit 20, the WAN side communication unit 31, and the LAN side communication unit 32, and performs predetermined arithmetic processing. Examples of the predetermined arithmetic processing include reception processing of a DNS inquiry message transmitted from the data transmitting / receiving apparatus 400. The detailed configuration of the main control unit 10 will be described later.

  The storage unit 20 stores (1) a control program for each unit, (2) an OS program, (3) an application program, and (4) various data to be read when the program is executed by the main control unit 10. Is. The storage unit 20 is configured by a nonvolatile storage device such as a flash memory. The storage unit 20 is configured by a volatile storage device such as a RAM (Random Access Memory), and is a work area for temporarily storing data in the course of executing the various programs described above by the main control unit 10. have.

  The storage unit 20 particularly includes a server address storage unit 21, a QoS target storage unit (second storage unit) 22, and a queue assignment information storage unit (first storage unit) 23.

  The server address storage unit 21 stores a set of the domain name and IP address of the server 600 in a readable state. The server address storage unit 21 may have a data structure as shown in Table 1 below, for example. Table 1 is a table showing an example of the data structure of the server address storage unit 21. As shown in Table 1, the server address storage unit 21 stores an entry including a set of “domain name” and “server IP address”. “Domain name” is a character string representing the domain name of the server 600. “Server IP address” is the IP address of the server 600.

  Note that the server address storage unit 21 may store a plurality of IP addresses in association with one domain name. This is because a secondary server may be constructed in order to distribute the load on the server 600 or to back up data. In Table 1, for example, “101.101.101.1” and “101.101.101.2” are stored as IP addresses of the server 600 having the domain name “sv1.vod.service-a.co.jp”.

  Next, the QoS target storage unit 22 includes the name of the service provided by the server 600, the domain name of the server 600, the transmission rate required to transmit the data flow transmitted from the server 600, and the server 600. A set of priority necessity information indicating whether to preferentially transmit the data flow to be transmitted is stored in a readable state. Note that the priority necessity information does not need to be stored in a configuration in which the user can set priority necessity information indicating whether or not to preferentially transmit (described later).

  The QoS target storage unit 22 can have a data structure as shown in Table 2 below, for example. Table 2 is a table showing an example of the data structure of the QoS target storage unit 22. In the example of Table 2, the QoS target storage unit 22 stores an entry including a set of “service name”, “domain name”, “required transmission rate”, and “priority necessity information”.

  “Service name” is a name of a service provided by the server 600. “Domain name” is a character string representing the domain name of the server 600.

  The “necessary transmission rate” is a value indicating a transmission rate necessary for transmitting the server 600 data flow. In general, since the transmission rate may increase momentarily (temporarily), store a value about several percent larger than the actually required transmission rate in the “required transmission rate”. Is desirable.

  The “priority necessity information” is priority necessity information indicating whether or not to preferentially transmit the data flow transmitted from the server 600. “Required” indicates that the data flow needs to be transmitted with priority, and “No” indicates that the data flow does not need to be transmitted with priority.

  Note that a data flow whose priority necessity information is “No” is handled in the HGW 101a in the same way as a non-priority data flow such as an FTP data flow. The value of the “priority necessity information” column can be set by the user using a QoS target setting screen 161 described later. Therefore, the user can set whether to preferentially transmit the priority data flow.

  It should be noted that the user can set priority necessity information indicating whether or not to preferentially transmit (set using a QoS target setting screen 161 described later) (that is, the user sets priority necessity information). In the case of a configuration incapable of being configured), the values in the “priority necessity information” column of all entries may be set to “necessary”, or the “priority necessity information” column may not be provided.

  In addition, the value of “required transmission rate” is calculated in a process of calculating a rate limit value LR when the limit rate calculation processing unit 145 described later sends a packet stored in the rate limit queue 144 to the LAN side communication unit 32. Referenced.

  In Table 2, for example, the transmission rate required for transmission of the data flow of the service “video distribution service A” provided by the server 600 having the domain name “* .vod.service-a.co.jp” is “ 10 Mbps ”and the value of the“ priority necessity information ”column is“ necessary ”, so that the data flow is preferentially transmitted.

  Here, the character “*” used in the “domain name” is a character representing an arbitrary character string. Therefore, for example, “sv1.vod.service-a.co.jp” and “sv2.vod.service-a.co.jp” are both expressed as “* .vod.service-a.co.jp”. included. Therefore, the domain names of the server 600 that provides the service “video distribution service A” exemplified above are “sv1.vod.service-a.co.jp” and “sv2.vod.service-a.co”. .jp "can be used. Furthermore, if the domain name is described by the expression “* .vod.service-a.co.jp”, for example, the server 600 having the domain name “sv3.vod.service-a.co.jp” Even if it is newly installed in the future, it is not necessary to update the entry in the QoS target storage unit 22. Similarly, the expression “vod * .service-d.com” includes domain names such as “vod001.service-d.com” and “vod002.service-d.com”. The domain name may be described by a regular expression that is generally used. For example, in a general regular expression, an arbitrary character of a specific type (alphabet, number, symbol) can be indicated, or an arbitrary character string of a specific number of characters can be indicated.

  Each entry in the QoS target storage unit 22 may be stored in advance for each service that can be provided by each server 600 at the time of factory shipment of the HGW 101a, for example. In this case, the HGW 101a vendor or the like independently investigates the domain name of each server 600, or obtains the domain name information of each server 600 from the service provider that operates the server 600. The grasped information is stored in advance. In addition, the user can update each entry in the QoS target storage unit 22 using any of the QoS target setting screens 161 and 162 described later. Regardless of whether or not the data flow of each service is currently transmitted, the QoS target storage unit 22 stores entries corresponding to all services that the HGW 101a may transfer packets. Is desirable.

  Next, the queue allocation information storage unit 23 is in a state where it can read information indicating whether the packet belonging to the data flow transmitted from the server 600 is stored in the rate non-limit queue 143 or the rate limit queue 144 To remember. Note that if the user does not have a configuration in which priority necessity information indicating whether or not to preferentially transmit is set, there is no need to distinguish between the rate non-limit queue 143 and the rate limit queue 144, and thus the rate non-limit queue It is not necessary to memorize the information indicating in which of 143 and rate limiting queue 144 the data is stored.

  The queue allocation information storage unit 23 can have a data structure as shown in Table 3 below, for example. Table 3 is a table showing an example of the data structure of the queue assignment information storage unit 23. In the example of Table 3, the queue assignment information storage unit 23 stores an entry including a set of “domain name”, “server IP address”, “client IP address”, “assignment queue”, and “last received date”. .

  “Domain name” is a character string representing the domain name of the server 600. As the value of the “domain name” column, the value of the “domain name” column of the QoS target storage unit 22 is copied. Similar to the data structure of the QoS target storage unit 22, the “domain name” may be described by an expression using “*” or a regular expression that is generally used. Note that the “domain name” column is not necessarily provided.

  “Server IP address” is the IP address of the server 600. “Client IP address” is the IP address of the data transmitting / receiving apparatus 400.

  The “assignment queue” is information indicating whether a packet belonging to the data flow transmitted from the server 600 is stored in the rate non-limit queue 143 or the rate limit queue 144. When the value in the “assignment queue” column is “rate unrestricted”, it indicates that the data is stored in the rate non-restricted queue 143, and when it is “rate limit”, it indicates that the value is stored in the rate limited queue 144.

  Note that if the user does not have a configuration in which priority necessity information indicating whether or not to preferentially transmit is set, it is not necessary to distinguish between the rate non-limit queue 143 and the rate limit queue 144, so The value of the “assignment queue” column may be “rate unrestricted”, or the “assignment queue” column may not be provided.

  The “assignment queue” column and the “priority necessity information” column of the QoS target storage unit 22 are columns that store substantially the same information. That is, when the user designates that the data flow needs to be transmitted with priority, the value of the “priority necessity information” column of the entry of the QoS target storage unit 22 is “necessary” and the queue The value of the “assignment queue” column in the assignment information storage unit 23 is “rate unrestricted”. When the user specifies that the data flow need not be transmitted with priority, the value in the “priority necessity information” column of the QoS target storage unit 22 is “No” and the queue allocation information The value of the “assignment queue” column of the storage unit 23 is “rate limit”. That is, if the value in the “priority necessity information” column is determined, the value in the “assignment queue” column is determined. However, by using the QoS target setting screens 161 and 162 described later, the user can individually update the value in the “priority necessity information” column and the value in the “assignment queue” column.

  “Last received date and time” is the date and time when the HGW 101a last received a packet belonging to the data flow transmitted from the server 600. This is used to determine timeout.

  In Table 3, for example, a server 600 having a domain name that matches the expression “* .vod.service-a.co.jp” (IP addresses are “101.101.101.1”, “101.101.101.2”, “101.101.101.3”). ”And“ 101.101.101.4 ”), the packet transmitted to the STB 401 whose IP address is“ 192.168.0.1 ”is stored in the“ rate unrestricted queue 143 ”, and The fact that the date and time when the HGW 101a last received the packet is “January 16, 2009 10:50:10” is stored.

  Each time at least one of “domain name”, “server IP address”, and “client IP address” is different, a different entry is stored in the queue assignment information storage unit 23. Accordingly, the domain name of the data flow transmission source server 600 is the same, but the IP address of the data transmission / reception device 400 that is the transmission destination of the data flow is different (that is, different data transmission / reception devices 400 have the same service data). When a flow is received), an entry corresponding to each is stored in the queue assignment information storage unit 23. Further, when the domain name of the data flow transmission source server 600 is different, but the IP address of the data transmission / reception device 400 of the transmission destination of the data flow is the same (that is, one data transmission / reception device 400 has different services). ), The corresponding entries are stored in the queue assignment information storage unit 23.

  Further, when the IP address of the data transmitting / receiving apparatus 400 is assigned using DHCP, there is a possibility that the data will be changed at the time of restart or the like. The MAC (Media Access Control) address of the transmission / reception device 400 may be stored. The MAC address of the data transmission / reception device 400 can be acquired, for example, by exchanging a communication protocol such as ARP (Address Resolution Protocol) between the HGW 101a and the data transmission / reception device 400, but is not an essential part of the present invention. The description is omitted here.

  The storage unit 20 is not necessarily provided in the HGW 101a, and may be configured as an external storage device that is connected to the HGW 101a in a readable state. For example, the storage unit 20 may be configured to be communicably connected to the HGW 101a as an external storage device on the Internet 701 or the home network 501.

  The WAN communication unit 31 communicates with a device connected via the access network 702. In this embodiment, communication with base station 703 is performed via access network 702. Therefore, the WAN side communication unit 31 has a general modem function and the like.

  The LAN side communication part 32 communicates with the apparatus connected via Ethernet. In the present embodiment, the LAN side communication unit 32 communicates with the data transmission / reception device 400 via the home network 501.

  Next, the main controller 10 will be described in detail. The main control unit 10 includes a packet transfer processing unit 11, a DNS processing unit (domain name / address extraction unit, address acquisition unit) 12, a queue assignment information generation processing unit (transmission control information generation unit, first priority necessity information acquisition unit). ) 13, a transmission rate control processing unit 14, a QoS target setting processing unit (priority necessity information setting unit) 16, and a QoS target update processing unit 17.

  First, the packet transfer processing unit 11 will be described. The packet transfer processing unit 11 first receives a packet received from the server 600 by the WAN side communication unit 31 via the access network 702 and a packet received from the data transmission / reception device 400 by the LAN side communication unit 32 via the home network 501. Whether or not the destination is the HGW 101a.

  As a result of the analysis, if the destination of the received packet is not the HGW 101a, and the destination of the received packet is a WAN side device (that is, the server 600), the packet transfer processing unit 11 Then, transfer processing of the received packet is performed. That is, the packet addressed to the WAN side device received from the data transmitting / receiving device 400 via the home network 501 is transferred to the WAN side communication unit 31.

  On the other hand, if the destination of the received packet is not the HGW 101a as a result of the analysis, and the destination of the received packet is a LAN side device (that is, the data transmitting / receiving device 400, etc.), a packet transfer processing unit 11 transmits the received packet to the transmission rate control processing unit 14 and causes the transmission rate control processing unit 14 to perform subsequent processing.

  Note that whether the destination of the packet is the LAN side or the WAN side can be determined by analyzing the IP address. This is a general routing process, and the description thereof will be given here. Omitted. Further, in packet transfer processing, NAT (Network Address Translation) processing and NAPT (Network Address Port Translation) processing are generally performed, but since they are not an essential part of the present invention, description thereof is omitted here. .

  If the packet transfer processing unit 11 analyzes the destination of the received packet packet and finds that the destination of the received packet is the HGW 101a, the packet transfer processing unit 11 further determines that the packet is a DNS inquiry message or DNS response message packet. It is analyzed whether or not. If it is found that the packet is a DNS inquiry message or DNS response message packet, the DNS processing unit 12 is caused to perform subsequent processing.

  Further, when the packet transfer processing unit 11 receives from the data transmitting / receiving device 400 a packet including a request to provide any of the QoS target setting screens 161 and 162 described later, the packet transfer processing unit 11 performs subsequent processing on the QoS target setting processing unit 16. Let it be done.

  Further, when receiving a packet including a request for access to the update server 606 from the data transmitting / receiving apparatus 400, the packet transfer processing unit 11 causes the QoS target update processing unit 17 to perform subsequent processing.

  Next, the DNS processing unit 12 will be described. The DNS processing unit 12 performs general processing relating to DNS. When the packet received by the packet transfer processing unit 11 is a DNS inquiry message packet transmitted from the data transmission / reception device 400, the DNS processing unit 12 first includes the domain of the inquiry target device included in the DNS inquiry message. The name and the IP address of the data transmitting / receiving apparatus 400 are extracted (domain name / address extracting means). Then, it is searched whether or not an entry including the extracted domain name is stored in the server address storage unit 21.

  As a result of the search, when an entry including the domain name is stored in the server address storage unit 21, the DNS processing unit 12 acquires an IP address corresponding to the domain name from the server address storage unit 21. (Address acquisition means) returns a DNS response message including the acquired IP address to the data transmission / reception apparatus 400 that is the transmission source of the DNS inquiry message via the packet transfer processing unit 11.

  On the other hand, if the entry including the domain name is not stored in the server address storage unit 21 as a result of the search, the DNS processing unit 12 sends a new DNS query including the domain name via the packet transfer processing unit 11. The message is transmitted to the DNS server 601. Thereafter, when a DNS response message for the new DNS inquiry message is received from the DNS server 601 via the packet transfer processing unit 11, a set of the domain name and the IP address included in the DNS response message is stored in the server address storage unit 21. The DNS response message is transferred to the data transmission / reception apparatus 400 that is the transmission source of the DNS inquiry message via the packet transfer processing unit 11.

  When receiving the DNS response message from the DNS server 601, the DNS processing unit 12 also acquires a TTL (Time To Live) included in the DNS response message. When the period indicated by the acquired TTL has elapsed after receiving the DNS response message, the pair of the domain name and the IP address contained in the DNS response message stored in the server address storage unit 21 is deleted. To do. Although the TTL value is included in the DNS response message returned to the data transmission / reception device 400 that is the transmission source of the DNS inquiry message, it is determined independently of the TTL value acquired from the DNS server 601, and the DNS cache is Use a short value so that it can be deleted early.

  Next, the queue assignment information generation processing unit 13 will be described. The queue assignment information generation processing unit 13 performs a queue assignment information generation process. The queue allocation information generation processing unit 13 updates the queue allocation information storage unit 23 as necessary after the DNS processing unit 12 transmits a DNS response message to the data transmission / reception device 400 that is the transmission source of the DNS inquiry message. .

  Specifically, the queue allocation information generation processing unit 13 first searches all entries in the QoS target storage unit 22 and the value of the “domain name” column is the domain of the query target device included in the DNS response message. Extract the entry that matches the name. At this time, if the entry is not extracted, the service provided by the server 600 to which the data transmitting / receiving apparatus 400 tries to access (that is, the server 600 having the domain name included in the DNS response message) is stored in the QoS target storage unit 22. Since the service is not managed, the packet transmitted from the server 600 is not a QoS target and is not preferentially transmitted. Therefore, in this case, the queue assignment information generation processing unit 13 ends the process. That is, the queue allocation information storage unit 23 is not updated.

  On the other hand, when an entry in which the value of the “domain name” column matches the domain name of the query target device included in the DNS response message is extracted from the QoS target storage unit 22, “ Get the value of "priority necessity information" column.

  Subsequently, the queue allocation information generation processing unit 13 searches all entries in the server address storage unit 21 and sets a value that matches the value in the “domain name” column of the entry extracted from the QoS target storage unit 22 to “domain”. The entry having in the “name” column is extracted. Then, by referring to the “server IP address” column of the extracted entry, the IP address of the server 600 to which the data transmitting / receiving apparatus 400 tries to access (that is, the server 600 having the domain name included in the DNS response message) is determined. get. If a plurality of IP addresses are applicable, all are acquired.

  Subsequently, the queue allocation information generation processing unit 13 uses the value of the “priority necessity information” column acquired from the QoS target storage unit 22, the IP address acquired from the server address storage unit 21, and the like. The storage unit 23 is updated (transmission control information generating means).

  Specifically, (1) the value in the “domain name” column is the domain name of the entry extracted from the QoS target storage unit 22, and (2) the value in the “server IP address” column is the server address storage unit. (3) The value of the “client IP address” column is the IP address of the data transmitting / receiving apparatus 400 that is the destination of the DNS response message, and (4) the value of the “assignment queue” column. Is “rate unrestricted” or “rate limit” (that is, when the value of the “priority necessity information” column of the entry acquired from the QoS target storage unit 22 is “necessary”, “rate unrestricted”, (If “No”, “rate limit”), (5) Create an entry in the queue allocation information storage unit 23 in which the value of the “last received date” column is a NULL value. .

  Note that the value of the “last received date” column may be the current system time. Further, when there are a plurality of IP addresses acquired from the server address storage unit 21, the number of generated entries is also increased accordingly.

  When the QoS target storage unit 22 does not store “priority necessity information” and the queue allocation information storage unit 23 does not store “allocation queue”, the queue allocation information generation processing unit 13 The process is performed as follows.

  First, the queue allocation information generation processing unit 13 searches all the entries in the QoS target storage unit 22, and an entry whose value in the “domain name” column matches the domain name of the query target device included in the DNS response message. To extract. If no entry is extracted, the process ends.

  Subsequently, the queue allocation information generation processing unit 13 searches all entries in the server address storage unit 21 and sets a value that matches the value in the “domain name” column of the entry extracted from the QoS target storage unit 22 to “domain”. The entry having in the “name” column is extracted. Then, by referring to the “server IP address” column of the extracted entry, the IP address of the server 600 to which the data transmitting / receiving apparatus 400 tries to access (that is, the server 600 having the domain name included in the DNS response message) is determined. get. If a plurality of IP addresses are applicable, all are acquired.

  Subsequently, the queue assignment information generation processing unit 13 updates the queue assignment information storage unit 23 using the IP address acquired from the server address storage unit 21 (transmission control information generation unit).

  Specifically, (1) the value in the “domain name” column is the domain name of the entry extracted from the QoS target storage unit 22, and (2) the value in the “server IP address” column is the server address storage unit. (3) the value of the “client IP address” column is the IP address of the data transmitting / receiving apparatus 400 that is the destination of the DNS response message, and (4) the “last received date” column An entry whose value is a NULL value is generated in the queue allocation information storage unit 23.

  Here, the queue assignment information generation processing performed by the queue assignment information generation processing unit 13 will be described with a specific example with reference to Table 1, Table 2, and Table 3. Here, it is assumed that the server address storage unit 21 stores data shown in Table 1, and the QoS target storage unit 22 stores data shown in Table 2. The queue assignment information storage unit 23 has a data structure shown in Table 3. Then, the DNS processing unit 12 performs processing for the DNS inquiry message transmitted from the STB 401 having the IP address “192.168.0.1” and whose domain name is “sv1.vod.service-a.co.jp”. Suppose that

  In this case, as described above, the queue allocation information generation processing unit 13 first extracts an entry including the domain name “sv1.vod.service-a.co.jp” from the QoS target storage unit 22. The character string “sv1.vod.service-a.co.jp” is included in the expression “* .vod.service-a.co.jp”. Therefore, an entry whose value of the “service name” column is “video distribution service A” is extracted. Note that the value in the “priority necessity information” column of the entry is “necessary”.

  Next, the queue allocation information generation processing unit 13 extracts an entry including the domain name “* .vod.service-a.co.jp” from the server address storage unit 21. Therefore, the entry in the “domain name” column of the server address storage unit 21 is “sv1.vod.service-a.co.jp” and “sv2.vod.service-a.co.jp”. An entry is extracted. Then, the values of the “server IP address” column of the entry are “101.101.101.1”, “101.101.101.2”, “101.101.101.3”, and “101.101.101.4”.

  The queue assignment information generation processing unit 13 then obtains the values of the “domain name” and “priority necessity information” columns obtained from the QoS target storage unit 22 and the “server” obtained from the server address storage unit 21. The data shown in Table 3 is stored in the queue assignment information storage unit 23 based on the value of the “IP address” column. That is, (1) the value of the “domain name” column is “* .vod.service-a.co.jp”, the value of the “server IP address” column is “101.101.101.1”, and the value of the “client IP address” column Is “192.168.0.1”, the entry in the “Allocation Queue” column is “Rate Unlimited”, (2) the value in the “Domain Name” column is “* .vod.service-a.co.jp”, “ An entry in which the value of the “server IP address” column is “101.101.101.2”, the value of the “client IP address” column is “192.168.0.1”, and the value of the “assignment queue” column is “rate unrestricted”; The domain name column value is "* .vod.service-a.co.jp", the "server IP address" column value is "101.101.101.3", and the "client IP address" column value is "192.168.0.1" , An entry whose value in the “Allocation Queue” column is “Rate Unlimited”, (4) “ "In name" column value is "* .vod.service-a.co.jp", "Server IP address" column value is "101.101.101.4", "Client IP address" column value is "192.168.0.1" , Each entry having a value of “rate unrestricted” in the “assignment queue” column is generated.

  Next, the transmission rate control processing unit 14 will be described. The transmission rate control processing unit 14 performs transmission rate control processing. The transmission rate control processing unit 14 transfers the packet transmitted from the packet transfer processing unit 11 to either the rate non-limit queue 143 or the rate limit queue 144 based on the entry stored in the queue assignment information storage unit 23. Perform the storing process. The packet stored in the rate limiting queue 144 is sent to the LAN side communication unit 32 while limiting the transmission rate, and the packet stored in the rate non-limiting queue 143 is transmitted without limiting the transmission rate. The data is sent to the LAN side communication unit 32. For this purpose, the transmission rate control processing unit 14 includes a packet distribution processing unit (source address / destination address extracting unit, second priority necessity information acquiring unit, communication packet storage unit) 141, packet transmission processing unit (data flow transmission). Control means) 142 and a limit rate calculation processing unit (priority transmission rate calculation means, transmission rate calculation means) 145.

  The packet distribution processing unit 141 stores the packet transmitted from the packet transfer processing unit 11 in either the rate non-limiting queue 143 or the rate limiting queue 144 based on the entry stored in the queue allocation information storage unit 23. The process to do is performed.

  Specifically, the packet distribution processing unit 141 first extracts the transmission source IP address and the transmission destination IP address from the packet transmitted from the packet transfer processing unit 11. Then, from the entry in the queue assignment information storage unit 23, the value in the “server IP address” column matches the extracted source IP address, and the value in the “client IP address” column matches the extracted destination. An entry matching the IP address is extracted. If there are a plurality of entries, all of them are extracted.

  When the entry is extracted, the packet distribution processing unit 141 acquires the value of the “assignment queue” column of the extracted entry. When the value of the “assignment queue” column is “rate unrestricted”, the value of the “server IP address” column and the value of the “client IP address” column of the extracted entry are respectively set to the source IP address and The packet having the transmission destination IP address is stored in the rate non-limitation queue 143.

  On the other hand, when the value of the “assignment queue” column is “rate limit”, the value of the “server IP address” column and the value of the “client IP address” column of the extracted entry are respectively set as the source IP address and The packet having the transmission destination IP address is stored in the rate limiting queue 144.

  When the entry is extracted, the value of the “last received date / time” column of the extracted entry is overwritten with the date / time when the HGW 101a received the packet. Note that not the reception date and time but the date and time when the packet was transmitted from the HGW 101a may be stored.

  If the entry is not extracted, the packet transmitted from the packet transfer processing unit 11 is stored in the rate limiting queue 144.

  Further, when the queue allocation information storage unit 23 is configured not to store the “allocation queue”, the packet distribution processing unit 141 sets the value of the “server IP address” column and the “client IP address” column of the extracted entry. Are stored in the rate unrestricted queue 143 as the transmission source IP address and the transmission destination IP address, respectively. Further, a packet that does not have the value of the “server IP address” column of the extracted entry as a source IP address or does not have the “client IP address” column of the extracted entry as a destination IP address. Is stored in the rate limiting queue 144.

  Note that the packet distribution processing unit 141 performs the packet transfer process regardless of whether or not it is in “rate limiting mode” (a state in which the transmission rate of packets stored in the rate limiting queue 144 should be limited as described later). The packet transmitted from the unit 11 is stored in either the rate non-limit queue 143 or the rate limit queue 144. That is, when not in the rate limit mode, all packets transmitted from the packet transfer processing unit 11 are not stored in the rate non-limit queue 143.

  Next, the packet transmission processing unit 142 includes a non-rate limiting queue 143 and a rate limiting queue 144, and transmits packets stored in these queues to the LAN side communication unit 32.

  When the packet transmission processing unit 142 transmits a packet stored in the rate non-limitation queue 143, the packet transmission processing unit 142 transmits the packet to the LAN side communication unit 32 without limiting the transmission rate (that is, preferentially transmits).

  On the other hand, when sending a packet stored in the rate limiting queue 144, it is first checked whether or not it is in the rate limiting mode. As a result, if it is not the rate limiting mode, the packet stored in the rate limiting queue 144 is sent to the LAN side communication unit 32 without limiting the transmission rate. In the rate limiting mode, the packet stored in the rate limiting queue 144 is transmitted to the LAN side communication unit 32 at a transmission rate with the rate limiting value LR calculated by the limiting rate calculation processing unit 145 as the upper limit ( In other words, it transmits at a lower priority).

  Note that when the QoS function described later is set to OFF on the QoS target setting screen 161 described later, the packet transmission processing unit 142 does not limit the transmission rate regardless of the rate limiting mode, and does not limit the rate. The packet stored in the queue 143 is sent to the LAN side communication unit 32.

  If the number of packets stored in the rate non-limit queue 143 exceeds a predetermined threshold, the packet transmission processing unit 142 determines that the number of packets stored in the rate non-limit queue 143 is in advance. Control is performed so that packets stored in the rate limiting queue 144 are not sent out until a predetermined threshold value is exceeded. This is because the packets stored in the rate non-limit queue 143 are preferentially transmitted.

  Further, the packet transmission processing unit 142 manages the “rate limiting mode”. The rate limiting mode is a state in which the transmission rate of packets stored in the rate limiting queue 144 is limited. Whether or not the rate limit mode is set is determined by checking whether or not a packet is stored in the rate non-limit queue 143. Specifically, when a packet is stored in the rate non-limit queue 143, it is necessary to preferentially transmit the packet stored in the rate non-limit queue 143, and therefore it is determined that the rate limit mode is set. . On the other hand, when a state in which no packets are stored in the rate non-limit queue 143 continues for a predetermined time (for example, several seconds), there is no packet to be preferentially transmitted, and therefore transmission of packets stored in the rate limit queue 144 is performed. Therefore, it is determined that the rate limit mode is not set.

  Information indicating whether or not the rate limit mode is set may be held in a memory or the like inside the packet transmission processing unit 142 or may be output to a file or the like so as to be readable.

  Next, the limit rate calculation processing unit 145 calculates a rate limit value LR when sending the packet stored in the rate limit queue 144 to the LAN side communication unit 32. As already described, LR is the difference between the line capacity AC of the access network 702 and the total value DC of the transmission rates necessary for transmission of the priority data flow.

  First, the limit rate calculation processing unit 145 obtains an AC value in advance based on information acquired from the base station 703 by the HGW 101a in the connection processing with the access network 702. The user may register the AC value in the HGW 101a in advance.

  The limit rate calculation processing unit 145 stores the obtained AC value and the registered AC value in the storage unit 20 (third storage unit) in a readable manner. The limit rate calculation processing unit 145 may be stored in a memory or a file.

  Next, the limit rate calculation processing unit 145 extracts the source IP address and the destination IP address from the packet stored in the rate non-limit queue 143. Then, from the entry in the queue assignment information storage unit 23, the value in the “server IP address” column matches the extracted source IP address, and the value in the “client IP address” column matches the extracted destination. An entry matching the IP address is extracted. Of the entries in the QoS target storage unit 22, entries whose values in the “domain name” column match the values in the “domain name” column of the entry extracted from the queue assignment information storage unit 23 are not duplicated. Extract. Then, the value of DC is obtained by summing up the “required transmission rate” values of all the extracted entries.

  Finally, the limit rate calculation processing unit 145 calculates the LR value by calculating the difference between the AC value and the DC value. Note that the calculated LR value is stored in a memory inside the limit rate calculation processing unit 145 or output to a file or the like in a state that the packet transmission processing unit 142 can refer to.

  Further, since the packet stored in the rate non-limit queue 143 changes with time, the limit rate calculation processing unit 145 calculates the value of LR in a predetermined cycle.

  Here, the transmission rate control processing performed by the transmission rate control processing unit 14 will be described with a specific example. Here, it is assumed that the queue allocation information storage unit 23 stores data shown in Table 3. Then, it is assumed that the video data flow is transmitted from the video distribution server 602 whose IP address is “101.101.101.1” to the STB 401 whose IP address is “192.168.0.1”.

  In this case, the packet transfer processing unit 11 transmits a packet belonging to the video data flow to the transmission rate control processing unit 14. Then, the packet distribution processing unit 141 of the transmission rate control processing unit 14 collates with the entry stored in the queue assignment information storage unit 23, and the value of the “server IP address” column is “101.101.101.1”. In addition, an entry whose value of the “client IP address” column is “192.168.0.1” is extracted. Then, the value of the “assignment queue” column of the extracted entry is referred to. In this case, since the value of the “assignment queue” column is “rate unrestricted”, the packet distribution processing unit 141 stores the video data packet in the rate unrestricted queue 143.

  Then, the packet transmission processing unit 142 transmits the video data packet from the rate unrestricted queue 143 without limiting the transmission rate (that is, preferentially transmits).

  On the other hand, it is assumed that the FTP data flow is transmitted from the FTP server 605 whose IP address is “201.201.201.1” to the PC 404 whose IP address is “192.168.0.4”.

  Also in this case, the packet transfer processing unit 11 transmits a packet belonging to the FTP data flow to the transmission rate control processing unit 14. Then, the packet distribution processing unit 141 of the transmission rate control processing unit 14 collates with the entry stored in the queue assignment information storage unit 23, but the entry is not extracted. Therefore, the packet distribution processing unit 141 stores the FTP data packet in the rate limiting queue 144.

  Then, the packet transmission processing unit 142 transmits the FTP data packet from the rate limiting queue 144 while limiting the transmission rate (in other words, transmits the FTP data packet at a lower priority). However, as described above, transmission is performed while limiting the transmission rate only in the rate limiting mode (that is, when there are packets transmitted from the rate non-limit queue 143 at the same time). When not in the rate limiting mode, the packet transmission processing unit 142 transmits the FTP data packet from the rate limiting queue 144 without limiting the transmission rate.

  Next, the QoS target setting processing unit 16 will be described. The QoS target setting processing unit 16 updates the data stored in the QoS target storage unit 22 and the queue assignment information storage unit 23 in response to a request received from the data transmitting / receiving apparatus 400 via the packet transfer processing unit 11. Predetermined data (for example, HTML data) constituting the QoS target setting screens 161 and 162 that are the user interfaces are transmitted to the data transmitting / receiving apparatus 400. That is, the QoS target setting processing unit 16 includes a general Web server function. Note that the QoS target setting screens 161 and 162 are screens on which the user of the data transmitting / receiving apparatus 400 can perform various settings regarding the queue assignment information generation processing and the transmission rate control processing in the HGW 101a. The QoS target setting screens 161 and 162 will be described later.

  Then, the QoS target setting processing unit 16 updates the data stored in the QoS target storage unit 22 based on the content input by the user of the data transmitting / receiving apparatus 400 on the QoS target setting screen 161. Further, the data stored in the QoS target storage unit 22 and the queue assignment information storage unit 23 are updated based on the contents input by the user of the data transmitting / receiving apparatus 400 on the QoS target setting screen 162. This update process will be described together with the description of the QoS target setting screens 161 and 162 described later. In addition, when it is necessary to update the display of the QoS target setting screen 161 or the QoS target setting screen 162 when the update process is performed, predetermined data (for example, HTML data) constituting them is transferred to the data transmitting / receiving device. 400.

  Further, the QoS target setting processing unit 16 updates the display of any of the QoS target setting screens 161 and 162 in response to the notification that the QoS target update processing unit 17 has generated a new entry in the QoS target storage unit 22. In order to do this, predetermined data (for example, HTML data) constituting the QoS target setting screens 161 and 162 is transmitted to the data transmitting / receiving apparatus 400.

  Next, the QoS target update processing unit 17 will be described. The QoS target update processing unit 17 communicates with the update server 606 via the packet transfer processing unit 11, and data (specifically, a service for adding a new entry in the QoS target storage unit 22 from the update server 606. Name, domain name, required transmission rate, and priority necessity information). The timing for performing the acquisition is not particularly limited. For example, the update server 606 may be accessed at a predetermined cycle to acquire the data. For example, a predetermined user operation may be performed on the QoS target setting screens 161 and 162. The update server 606 may be accessed using the reception of the fact that the data has been received from the data transmitting / receiving apparatus 400 as a trigger to acquire the data.

  Then, the QoS target update processing unit 17 generates a new entry in the QoS target storage unit 22 based on the acquired data. Further, at this time, the QoS target setting processing unit 16 is notified that the new entry has been generated.

  Note that the processing of the QoS target update processing unit 17 will also be described when the QoS target setting screens 161 and 162 described later are described.

(Processing flow when HGW receives a packet)
Next, an outline of a processing flow when the HGW 101a receives a packet will be described with reference to FIG. FIG. 6 is a flowchart showing an outline of a processing flow when the HGW 101a receives a packet.

  First, immediately after activation, the HGW 101a waits for reception of a packet (step S501). When the packet transfer processing unit 11 receives the packet (YES in step S501), it analyzes whether the destination of the received packet is the HGW 101a (step S502).

  As a result of the analysis, it is found that the destination of the received packet is not HGW 101a (NO in step S502), and the destination of the received packet is on the access network 702 side (that is, the WAN side) (step S502). If NO in S503, the packet transfer processing unit 11 performs the transfer process for the received packet (step S504). That is, the packet received from the data transmitting / receiving apparatus 400 is transferred to the WAN side communication unit 31.

  On the other hand, if the destination of the received packet is the home network 501 side (that is, the LAN side) in step S503 (YES in step S503), the packet is transmitted to the transmission rate control processing unit 14 for transmission. The rate control processing unit 14 performs transmission rate control processing (step S505). That is, the packet received from the server 600 is sent to the LAN side communication unit 32 while being buffered in its own device. The flow of the transmission rate control process will be described later using another flowchart.

  On the other hand, as a result of the analysis in step S502, if it is found that the destination of the received packet is HGW 101a (YES in step S502), packet transfer processing unit 11 further determines that the packet is a DNS inquiry message packet or It is analyzed whether the packet is a DNS response message packet (hereinafter referred to as a DNS packet) (step S506).

  If it is determined that the packet is a DNS packet (YES in step S506), DNS processing unit 12 performs general processing relating to DNS (step S507) as described above. That is, exchange with the DNS server 601 is performed as necessary, and finally a DNS response message is transmitted to the transmission source of the DNS inquiry message. The inquiry target IP address obtained as a result of the inquiry to the DNS server 601 is stored in the server address storage unit 21.

  After transmitting the DNS response message to the DNS inquiry message transmission source, the queue allocation information generation processing unit 13 performs queue allocation information generation processing (step S508). The flow of queue allocation information processing will be described later using another flowchart.

  If it is determined in step S506 that the received packet is not a DNS packet (NO in step S506), processing corresponding to the received packet is performed (step S509). For example, the display processing of the QoS target setting screens 161 and 162 and the like are included in the processing performed in step S509.

  In this flowchart, the process when the packet transfer processing unit 11 receives a packet including the content for requesting provision of the QoS target setting screens 161 and 162 and a packet including the content for requesting access to the update server 606 is described. The flow is omitted. Also, processing of packets not related to the present invention is omitted.

(Flow of queue allocation information generation process)
Next, an outline of a flow of queue assignment information generation processing performed by the queue assignment information generation processing unit 13 will be described with reference to FIG. FIG. 7 is a flowchart showing an outline of the flow of queue assignment information generation processing performed by the queue assignment information generation processing unit 13. Note that the QoS target storage unit 22 has the data structure shown in Table 2, and the queue assignment information storage unit 23 has the data structure shown in Table 3.

  First, when the DNS processing unit 12 transmits a corresponding DNS response message via the packet transfer processing unit 11 to the transmission source of the DNS inquiry message received by the packet transfer processing unit 11 (YES in step S701). ), The queue allocation information generation processing unit 13 searches all the entries in the QoS target storage unit 22, and the value of the “domain name” column matches the domain name of the query target device included in the DNS response message. An entry is extracted (step S702).

  If the entry is extracted (YES in step S703), the queue assignment information generation processing unit 13 searches all entries in the server address storage unit 21, and the “domain” of the entry extracted in step S702. An entry having a value matching the value in the “name” column in the “domain name” column is extracted (step S704).

  If the entry is extracted (YES in step S705), the queue allocation information generation processing unit 13 generates the following entry in the queue allocation information storage unit 23 (step S706). That is, (1) the domain name of the entry extracted in step S704 is set to the value of the “domain name” column, and (2) the entry extracted in step S704 is set to the value of the “server IP address” column. (3) The IP address of the data transmission / reception device 400 that is the destination of the DNS response message is set as the value of the “client IP address” column, and (4) the value of the “assignment queue” column is set. Sets “rate unrestricted” when the value of the “priority necessity information” column of the entry extracted in step S702 is “necessary”, and sets “rate limit” when “not”, 5) An entry in which NULL is set as the value of the “last received date” column is generated.

  Note that the value of the “last received date” column may store the current system time. If there are a plurality of entries extracted in step S704, a plurality of entries generated as described above are generated accordingly.

  Then, after step S706, or when an entry is not extracted at step S702 (NO at step S703), or when an entry is not extracted at step S704 (NO at step S705), it is included in the DNS response message. Whether the queue assignment information generation processing has been performed for all the domain names of the devices to be inquired (in other words, a response for a plurality of domain names is made in one DNS response message, and It is determined whether or not the queue allocation information generation process has been performed for all (step S707). If queue assignment information generation processing has not been performed for all domain names (NO in step S707), steps S702 to S706 are repeated for unprocessed domain names.

  On the other hand, if queue assignment information generation processing has been performed for all domain names (YES in step S707), and if a DNS response message has not been transmitted in step S701 (NO in step S701), queue assignment information The generation processing unit 13 ends the process (end).

(Flow of transmission rate control processing)
Next, an outline of the flow of transmission rate control processing performed by the transmission rate control processing unit 14 will be described with reference to FIG. FIG. 8 is a flowchart showing an outline of the flow of transmission rate control processing performed by the transmission rate control processing unit 14. The queue assignment information storage unit 23 has a data structure shown in Table 3.

  First, the packet distribution processing unit 141 extracts the source IP address and the destination IP address included in the packet transmitted from the packet transfer processing unit 11 (step S901).

  Then, the packet distribution processing unit 141 searches all entries in the queue assignment information storage unit 23, and the value of the “server IP address” column matches the transmission source IP address of the packet transmitted from the packet transfer processing unit 11. Then, an entry whose value in the “client IP address” column matches the destination IP address of the packet is extracted (step S902). If there are a plurality of entries, all of them are extracted.

  If the entry is extracted (YES in step S903), the transmission rate control processing unit 14 acquires the value of the “assignment queue” column of the extracted entry (step S904). If the value of the “assignment queue” column is “rate unrestricted”, the packet transmitted from the packet transfer processing unit 11 is stored in the rate unrestricted queue 143 (step S905). Subsequently, the packet transmission processing unit 142 transmits the packet stored in the rate unrestricted queue 143 to the LAN side communication unit 32 without limiting the transmission rate (step S906).

  On the other hand, if no entry is extracted (NO in step S903), and if the value of the “assignment queue” column examined in step S904 is “rate limiting”, the packet distribution processing unit 141 includes a packet transfer processing unit. 11 is stored in the rate limiting queue 144 (step S907).

  Subsequently, the packet transmission processing unit 142 checks whether or not it is currently in the rate limiting mode (step S908). If not in the rate limiting mode (NO in step S908), the packet stored in the rate limiting queue 144 is sent to the LAN side communication unit 32 without limiting the transmission rate (step S909). On the other hand, when the rate limit mode is set (YES in step S908), the packet transmission processing unit 142 limits the transmission rate so as to be equal to or less than the rate limit value LR calculated by the limit rate calculation processing unit 145, while limiting the rate. The packet stored in the queue 144 is sent to the LAN side communication unit 32 (step S910).

  In practice, a packet may not be sent from the queue immediately after being stored in each queue. When a new packet is received by the WAN communication unit 31 while the packet is stored in the queue, the received packet and the packet currently stored in the queue are transmitted in parallel. Perform rate control processing.

  In addition, when the number of packets stored in the rate non-limit queue 143 exceeds a predetermined threshold, the rate stored as a packet stored in the rate non-limit queue 143 is preferentially transmitted. Control is performed so that packets stored in the rate limiting queue 144 are not transmitted until the number of packets stored in the non-limiting queue 143 falls below a predetermined threshold.

(Simplified version of QoS target setting screen)
Next, the QoS target setting screens 161 and 162 will be described with reference to FIGS. 9 and 10. First, FIG. 9 is a schematic diagram illustrating a screen example of a simple version QoS target setting screen 161 with a few items that can be set.

  This screen is provided by the QoS target setting processing unit 16 including a general Web server function in response to a request from the data transmitting / receiving apparatus 400, and is accessed by a user of the data transmitting / receiving apparatus 400 using a Web browser or the like. To do. As a method for accessing this screen, a link for moving to this screen is provided on a screen for setting the routing function of the HGW 101a (general router setting screen). Alternatively, the user may directly input the URL of this screen into the Web browser. Further, an input / output device may be connected to the HGW 101a so that the setting can be performed from the connected input / output device.

  In this screen, as shown in the figure, (1) an input field N1 in which the user can input whether to turn on or off the QoS function, and (2) a video distribution service provided by the server 600 is displayed. An input field N2 is provided where the user can input whether or not to preferentially enjoy (that is, whether or not the video data flow is preferentially transmitted). Here, a pull-down menu, a list box, and the like are assumed as the input fields N1 and N2, but are not particularly limited.

  Here, “turning on the QoS function” refers to enabling the rate limiting mode. The “turning off the QoS function” refers to disabling the rate limiting mode. Therefore, when the QoS function is set to OFF, even in the rate limiting mode, the HGW 101a sends the packet stored in the rate limiting queue 144 to the LAN side communication unit 32 without limiting the transmission rate. Send it out.

  Note that it is conceivable that the QoS function is turned off when any QoS processing is performed in a device other than the HGW 101a and inconvenience occurs when these processing and the QoS processing according to the present invention are simultaneously used. For example, when the server 600 transmits a packet after giving a DSCP (Differentiated Services Code) value in advance, a problem may occur if the transmission rate is limited by the HGW 101a. For example, when there is a mismatch between the priority set in the server 600 and the transmission rate restriction performed in the HGW 101a, the packet is not transmitted with the priority set in the server 600.

  Further, information indicating whether the QoS function is turned on or off is stored in the storage unit 20, and when the QoS target setting processing unit 16 provides this screen, the QoS function is turned on or turned off. Is read from the storage unit 20, and a value is displayed in the input field N1 according to the read value.

  Also, the timing for storing the information indicating whether the QoS function is turned on or off in the storage unit 20 may be the time when there is an input in the input field N1, or the “OK” button B3 at the bottom of this screen is pressed. It may be when it is pressed. Further, when the QoS function is set to OFF, the input field N2 and the like may be controlled so that the user cannot input.

  Next, the input field N2 will be described. The QoS target setting processing unit 16 reads the contents of the QoS target storage unit 22 and displays a value in the input field N2. Specifically, the value in the “priority necessity information” column of the QoS target storage unit 22 is read and displayed for each service name. If the value of the “priority necessity information” column is “necessary”, the QoS target setting processing unit 16 converts it to “Yes” as shown in the figure and displays it in the “priority necessity information” column. If the value is “No”, it is converted to “No” as shown and displayed.

  When there is an input from the user in the input field N2, the QoS target setting processing unit 16 updates the QoS target storage unit 22. Specifically, an entry in the QoS target storage unit 22 having a service for which priority is input in the input field N2 as the value of the “service name” column is extracted, and the “priority necessity information” column of the entry is extracted. Update the value to “Required”. In addition, an entry having a service for which no priority is input in the input field N2 as a value in the “service name” column is extracted, and the value in the “priority necessity information” column of the entry is updated to “not”. .

  Note that the update timing is not limited to when there is an input from the user in the input field N2, but may be when the “Determine” button B3 on the QoS target setting screen 161 is pressed.

  As described above, the reason why the user simply inputs whether priority is given or not is that a user who is not familiar with QoS setting can relatively easily make settings related to QoS. A user who wants to make detailed settings can make various settings on a detailed version QoS target setting screen 162, which will be described later, by pressing the “detailed settings” button B1.

  Next, the “add service” button B2 will be described. When the user presses the “add service” button B 2, the QoS target update processing unit 17 communicates with the update server 606, and data (service) for adding a new entry in the QoS target storage unit 22 from the update server 606. Name, domain name, required transmission rate, and priority necessity information). For example, as data not stored in the QoS target storage unit 22 in the update server 606, the service name is “video distribution server E”, the domain name is “service-e.co.jp”, and the required transmission rate is “15 Mbps”. When there is a set of data whose priority necessity information is “necessary”, the data is acquired. Then, the QoS target update processing unit 17 generates a new entry in the QoS target storage unit 22 based on the acquired data. In the above example, the value of the “service name” column is “video distribution server E”, the value of the “domain name” column is “service-e.co.jp”, the value of the “required transmission rate” column is “15 Mbps”, An entry whose value in the “priority necessity information” column is “necessary” is generated.

  Note that the timing for performing the acquisition is not limited to when the user presses the “add service” button B2, and for example, the data may be acquired by accessing the update server 606 at a predetermined cycle. . At this time, when a new entry is generated in the QoS target storage unit 22, a predetermined confirmation message may be displayed to the user.

  In addition, when the QoS target update processing unit 17 generates the new entry in the QoS target storage unit 22, the QoS target setting processing unit 16 is notified of this. The QoS target setting processing unit 16 that has received the notification uses predetermined data (for example, HTML data) constituting the QoS target setting screen 161 as the data transmission / reception device 400 in order to update the simplified QoS target setting screen 161. Send to. For example, in the above-described example, the predetermined data configured to display the input field N2 on which the user can input whether or not to preferentially enjoy the service provided by the “video distribution server E”. (Eg, HTML data) is transmitted to the data transmitting / receiving apparatus 400.

(Detailed version of QoS target setting screen)
Next, a screen example of the detailed version QoS target setting screen 162 will be described with reference to FIG. FIG. 10 is a schematic diagram illustrating a screen example of the detailed version QoS target setting screen 162.

  This screen is provided by the QoS target setting processing unit 16 in response to a request from the data transmission / reception device 400, and is accessed by a user of the data transmission / reception device 400 using a Web browser or the like. This screen allows more detailed settings than the simplified QoS target setting screen 161 shown in FIG.

  Although it is assumed that when the “detailed setting” button B1 is pressed on the simplified version QoS target setting screen 161 shown in FIG. 9, the screen is transitioned to this screen, the present invention is not limited to this. A link for moving to this screen may be provided on a screen (general router setting screen) for performing settings related to the routing function and the like of the HGW 101a. You may enter directly.

  In this screen, as shown, (1) the name of the video distribution service, (2) the domain name of the video distribution service, (3) the transmission rate required by the data flow transmitted by the video distribution service, (4 ) Device name of the data transmission / reception device 400 receiving the data flow of the video distribution service, (5) IP address of the data transmission / reception device 400, (6) The data transmission / reception device 400 gives priority to the video distribution service. Whether to enjoy (that is, whether to preferentially transmit the video data flow) and (7) the current transmission rate of the data flow of the video distribution service for each data transmitting / receiving device 400 is displayed.

  Note that the above (4) and (7) are not necessarily displayed. Further, in addition to the IP address of (5) above, the MAC address of the data transmitting / receiving apparatus 400 may be displayed.

  As for the above (1), (2), (3), and (6), the contents of the QoS target storage unit 22 are read and displayed. Specifically, the value of the “service name” column, the value of the “domain name” column, the value of the “necessary transmission rate” column, and the value of the “priority necessity information” column of the QoS target storage unit 22 are respectively displayed. . For (5) above, the contents of the queue assignment information storage unit 23 are read and displayed. Specifically, the value in the “client IP address” column of the queue assignment information storage unit 23 is displayed.

  Note that the above (4) may be displayed by the HGW 101a using the predetermined communication protocol acquired from the data transmitting / receiving apparatus 400 or input by the user.

  In the above (7), the HGW 101a may measure and display the transmission rate of each data flow. For example, the average rate for the past 1 second and the past instantaneous maximum rate are displayed. Since the transmission rate changes sequentially, it is re-measured at a predetermined period and redisplayed. Further, instead of redisplaying at a predetermined cycle, the transmission rate calculated when the QoS target setting screen 162 is displayed may be continuously displayed.

  In (3) above, a numerical value indicating the transmission rate can be input in the input field N3. In (6) above, priority necessity information can be input in the input field N4. ), An arbitrary character string can be input in the input field N5. The input fields N3 and N4 are assumed to be pull-downs and list boxes, and the input field N5 is assumed to be a text box, but is not particularly limited.

  When the transmission rate is input in the input field N3, the QoS target setting processing unit 16 updates the QoS target storage unit 22. Specifically, an entry of the QoS target storage unit 22 having the service whose transmission rate is input in the input field N3 as the value of the “service name” column is extracted, and the value of the “necessary transmission rate” column of the entry is extracted. Update with the entered value.

  Note that the timing of the update is not limited to when the user inputs in the input field N3, and may be when the “OK” button B5 on the QoS target setting screen 162 is pressed.

  When priority necessity information is input in the input field N4, the QoS target setting processing unit 16 updates the queue allocation information storage unit 23. Specifically, it has the domain name of the service whose value is input in the input field N4 as the value of the “domain name” column, and the IP address of the device whose value is input in the input field N4 is “client IP address” The entry of the queue assignment information storage unit 23 having the value of the “column” is extracted, and the value of the “assignment queue” column of the entry is updated. If the value of the input field N4 is “yes”, the value of the “assignment queue” column is updated to “rate unrestricted”, and if the value of the input field N4 is “not”, the “assignment queue” column is updated. Update the value to “Rate Limit”.

  Note that the update timing is not limited to when the user inputs in the input field N4, and may be when the “Determine” button B5 on the QoS target setting screen 162 is pressed.

  In addition, the reason why the data transmission / reception apparatus 400 can input whether or not to preferentially enjoy the video distribution service in this way is, for example, the data transmission / reception receiving the data flow of the video distribution service A When there is an STB 401 and a PC 404 as the device 400, the data flow of the video distribution service A to the STB 401 is to be transmitted with priority, but the data flow of the video distribution service A to the PC 404 may not be transmitted with priority. This is because it is desirable that the data can be set for each data transmitting / receiving device 400.

  When the domain name is input to the user in the input field N5, the QoS target setting processing unit 16 updates the QoS target storage unit 22. Specifically, the entry of the QoS target storage unit 22 having the service whose domain name is input to the user in the input field N5 as the value of the “service name” column is extracted, and the value of the “domain name” column of the entry is extracted. Update with the domain name entered above.

  For a video distribution service that does not have a data transmission / reception device 400 that receives a data flow, (4) displays “None”, and (5), (6), and (7) indicate “−”. The input field N4 may be displayed so that the user cannot input it. In the screen shown in FIG. 10, the video distribution service C and the video distribution service D correspond to this.

  In addition, when the data transmission / reception device 400 that receives the data flow of the video distribution service is increased or decreased while this screen is displayed, the QoS target setting screen is again displayed in order to reflect the increase / decrease on this screen. Predetermined data (for example, HTML data) that constitutes 162 may be transmitted to the data transmitting / receiving apparatus 400.

  Next, the “add service” button B4 will be described. The operation when the user presses the “Add Service” button B4 is the same as when the user presses the “Add Service” button B2 on the screen shown in FIG. That is, the QoS target update processing unit 17 communicates with the update server 606, and adds data (a set of service name, domain name, and necessary transmission rate) for adding a new entry in the QoS target storage unit 22 from the update server 606. ) To get. Then, the QoS target update processing unit 17 generates a new entry in the QoS target storage unit 22 based on the acquired data. When the QoS target update processing unit 17 generates the new entry in the QoS target storage unit 22, the QoS target setting processing unit 16 notifies the QoS target setting processing unit 16 to that effect, and the QoS target setting processing unit 16 The detailed version of the QoS target setting screen 162 is updated so as to display the contents of.

(Transition of transmission bandwidth used by data flow in access network)
Next, with reference to FIG. 11, a description will be given of the use state of the transmission band in the access network 702 when the transmission rate of the data flow sent to the home network 501 is limited by the HGW 101a. FIG. 11 is a schematic diagram illustrating an example of temporal transition of the transmission band used in the access network 702 when the transmission rate of the data flow transmitted to the home network 501 is limited by the HGW 101a.

  Note that the line capacity of the access network 702 in this example is 70 Mbps, and the line capacity of the Internet 701 and the home network 501 is 100 Mbps. Further, it is assumed that the QoS target storage unit 22 stores the data shown in Table 2. Then, the FTP data flow from the FTP server 605, the video data flow from the video distribution server 602 to the video distribution service A, the video data flow from the video distribution server 603 to the video distribution service B, and the video distribution service C from the video distribution server 604 to each other. Video data flows are transmitted respectively.

  First, it is assumed that only the FTP data flow is transmitted until time T1. At this time, since the entry having the domain name of the FTP server 605 is not stored in the queue allocation information storage unit 23, the packet distribution processing unit 141 stores the packet of the FTP data flow in the rate limiting queue 144. However, at this point, since there is no data flow stored in the rate non-limit queue 143, the rate limit mode is not set.

  Therefore, the packet transmission processing unit 142 transmits the FTP data flow packet stored in the rate limiting queue 144 without limiting the transmission rate. As a result, the packet of the FTP data flow is transmitted so as to make maximum use of 100 Mbps, which is the line capacity of the home network 501.

  Therefore, the transmission rate of the FTP data flow in the access network 702 at this point is 70 Mbps, which is the line capacity of the access network 702, as illustrated. As shown in the figure, the transmission rate of the FTP data flow slightly increases and decreases with the passage of time (the concave portion of the graph shown in FIG. 11). In the figure, the range of increase / decrease is a constant time width and a constant rate width, but this is for simplification of explanation, and in practice, the fluctuation range of time and rate is not always constant. The same applies to other data flows.

  Next, it is assumed that transmission of the video data flow of the video distribution service A is started from time T1. Since the entry having the domain name of the video distribution server 602 is stored in the queue assignment information storage unit 23 and the value of the “assignment queue” of the entry is “rate unrestricted”, the packet distribution processing unit 141 Stores the packet of the video data flow of the video distribution service A in the rate unrestricted queue 143.

  Therefore, since the rate limit mode is entered from this point, the packet transmission processing unit 142 limits the packets of the FTP data flow stored in the rate limit queue 144 so that the transmission rate is equal to or less than the rate limit value LR. Send it out.

  At this time, the line capacity of the access network 702 is 70 Mbps, and the necessary transmission rate of the video data flow of the video distribution service A is 10 Mbps (which can be understood by referring to the QoS target storage unit 22). The rate limit value LR calculated by the calculation processing unit 145 is 60 Mbps (= 70 Mbps-10 Mbps).

  Therefore, the packet transmission processing unit 142 transmits the packets stored in the rate limiting queue 144 with a limit of 60 Mbps.

  Therefore, the transmission rate of the FTP data flow in the access network 702 at this time is 60 Mbps as shown in the figure. Since the video data flow of the video distribution service A (required transmission rate is 10 Mbps) is transmitted at the remaining 10 Mbps, it is possible to suppress the occurrence of a transmission delay of the video data flow.

  In FIG. 11, it is described that the transmission rate of the FTP data flow is immediately limited to 60 Mbps at time T1, but to be precise, the transmission rate of the FTP data flow gradually decreases from time T1. In addition, the transmission rate of the video data flow of the video distribution service A gradually increases from time T1. However, in the same figure, description is abbreviate | omitted for the simplification of description.

  In addition, during the period from time T11 to time T12, the transmission rate of the video data flow of the video distribution service A is temporarily high (10 Mbps or more). As already described, in the HGW 101a, the packet stored in the rate non-limit queue 143 is transmitted with higher priority than the packet stored in the rate limit queue 144. Thus, when the transmission band is insufficient as described above. As shown, the transmission band used by the FTP data flow decreases, and the transmission band of the video data flow of the video distribution service A increases.

  Further, for example, during the period from time T13 to time T14, the FTP data flow uses all of the limited 60 Mbps transmission band, but the transmission band of the video data flow of the video distribution service A is vacant. Yes. The reason why such a vacancy is generated is that the “required transmission rate” stored in the QoS target storage unit 22 is usually set to be larger than the actually required transmission rate. However, since the transmission rate of the FTP data flow is limited, even if there is a vacancy in the transmission band as described above, the FTP data flow is not transmitted using that vacancy.

  Next, it is assumed that transmission of the video data flow of the video distribution service B is started from time T2. Since the entry having the domain name of the video distribution server 603 is stored in the queue assignment information storage unit 23 and the value of the “assignment queue” of the entry is “rate unrestricted”, the packet distribution processing unit 141 Stores the packet of the video data flow of the video distribution service B in the rate unrestricted queue 143. Therefore, the video data flows of the video distribution service A and the video distribution service B are stored in the rate unrestricted queue 143 from time T2.

  Therefore, the rate limiting mode is continuously maintained, and the packet transmission processing unit 142 transmits the packet of the FTP data flow stored in the rate limiting queue 144 while limiting the transmission rate to be equal to or less than the rate limiting value LR. To do.

  At this time, the line capacity of the access network 702 is 70 Mbps, the required transmission rate of the video data flow of the video distribution service A is 10 Mbps, and the required transmission rate of the video data flow of the video distribution service B is 15 Mbps. The rate limit value LR calculated by the limit rate calculation processing unit 145 is 45 Mbps (= 70 Mbps-10 Mbps-15 Mbps).

  Therefore, the packet transmission processing unit 142 transmits the FTP data flow packet stored in the rate limiting queue 144 to 45 Mbps.

  Therefore, the transmission rate of the FTP data flow in the access network 702 at this time is 45 Mbps as shown in the figure. Since the video data flow of the video distribution service A (required transmission rate is 10 Mbps) and the video data flow of the video distribution service B (required transmission rate is 15 Mbps) are transmitted at the remaining 25 Mbps, the transmission delay of the video data flow Etc. can be suppressed.

  Next, it is assumed that transmission of the video data flow of the video distribution service C is started from time T3. Since the entry having the domain name of the video distribution server 603 is stored in the queue assignment information storage unit 23 and the value of the “assignment queue” of the entry is “rate limiting”, the packet distribution processing unit 141 The video data flow packet of the video distribution service C is stored in the rate limiting queue 144. That is, from time T3, the FTP data flow and the video data flow of the video distribution service C are stored in the rate limiting queue 144, and the video data flows of the video distribution service A and the video distribution service B are stored in the rate non-limit queue. 143.

  Therefore, the rate limit value LR calculated by the limit rate calculation processing unit 145 remains 45 Mbps.

  Then, the packet transmission processing unit 142 transmits the FTP data flow stored in the rate limiting queue 144 and the video data flow packet of the video distribution service C in such a way that the total is 45 Mbps or less.

  Therefore, the transmission rate of the FTP data flow in the access network 702 and the video data flow of the video distribution service C at this time is 45 Mbps as illustrated. Since the video data flow of the video distribution service A (required transmission rate is 10 Mbps) and the video data flow of the video distribution service B (required transmission rate is 15 Mbps) are transmitted at the remaining 25 Mbps, the video distribution service A and the video With respect to the video data flow of the distribution service B, it is possible to suppress the occurrence of transmission delay and the like.

  In this case, the video data flow of the video distribution service C uses the transmission band with the same priority as the FTP data flow. However, since it is not always possible to secure a sufficient transmission band so that transmission delay and jitter do not occur, in the data transmitting / receiving apparatus 400 that receives the video data flow of the video distribution service C, there is a possibility that the reproduction of video and the like may be disturbed. is there.

  Next, when transmission of the video data flow of the video distribution service C is completed at time T4, the packet transmission processing unit 142 stores the FTP data flow stored in the rate limiting queue 144 as in the period from time T2 to T3. Are transmitted with a limit of 45 Mbps.

  Next, when transmission of the video data flow of the video distribution service B is completed at time T5, the packet transmission processing unit 142 performs the FTP data flow stored in the rate limiting queue 144 as in the period from time T1 to T2. Are transmitted with a limit of 60 Mbps.

  Finally, when the transmission of the video data flow of the video distribution service A is completed at time T6, the packet transmission processing unit 142 transmits the packet of the FTP data flow stored in the rate limiting queue 144 as before time T1. , Send without limiting the transmission rate.

  In the above description, it is assumed that the FTP data flow, the video data flow of the video distribution service A, the video data flow of the video distribution service B, and the video data flow of the video distribution service C are transmitted one by one. This is the same even when a plurality of the same video data flows are transmitted. For example, when two video data flows of the video distribution service A are transmitted when the FTP data flow is transmitted, the packet transmission processing unit 142 transmits the packet of the FTP data flow stored in the rate limiting queue 144. And 50 Mbps (= 70 Mbps-10 Mbps × 2).

[Embodiment 2]
Another embodiment of the present invention will be described below with reference to FIGS. In the present embodiment, a description will be given of a mode in which the HGW 101 limits the transmission rate of the non-priority data flow based on the rate limit value LR calculated from the AC value and the DC value obtained by the combination B method described above. To do. Note that the HGW 101 according to the present embodiment is particularly referred to as an HGW 101b.

  For convenience of explanation, members having the same functions as those shown in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Similarly, the same processes as those shown in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

(Configuration of HGW)
Next, a schematic configuration of the HGW 101b as the communication control device 100 will be described with reference to FIG. FIG. 12 is a block diagram illustrating a schematic configuration of the HGW 101b.

  As shown in FIG. 12, the HGW 101b includes a main control unit 10b, a storage unit 20b, a WAN side communication unit 31, and a LAN side communication unit 32.

  The storage unit 20b newly includes a rate information storage unit (third storage unit) 24 in addition to the storage unit 20 included in the HGW 101a. The rate information storage unit 24 stores the AC value that is the line capacity of the access network 702 and the DC value that is the total value of the transmission rates necessary for transmission of the priority data flow in a readable state. is there.

  Next, the main control unit 10b controls the storage unit 20b, the WAN side communication unit 31, and the LAN side communication unit 32, and performs predetermined arithmetic processing.

  The main control unit 10b includes a packet transfer processing unit 11, a DNS processing unit 12, a queue allocation information generation processing unit 13, a transmission rate control processing unit 14b, a QoS target setting processing unit (priority necessity information setting unit) 16b, and a QoS target. An update processing unit 17 is included.

  The transmission rate control processing unit 14b includes a packet distribution processing unit 141, a packet transmission processing unit (data flow transmission control unit) 142b, and a limit rate calculation processing unit (priority transmission rate calculation unit, transmission rate calculation unit) 145b. .

  Similar to the packet transmission processing unit 142, the packet transmission processing unit 142b includes a rate non-limiting queue 143 and a rate limiting queue 144, and transmits packets stored in these queues to the LAN side communication unit 32. When a packet stored in the rate non-limit queue 143 is transmitted, the packet is transmitted to the LAN side communication unit 32 without limiting the transmission rate (that is, transmitted preferentially). On the other hand, when the packet stored in the rate limiting queue 144 is sent, if it is not in the rate limiting mode, the packet stored in the rate limiting queue 144 is sent to the LAN side communication unit 32 without limiting the transmission rate. . In the rate limiting mode, the packet stored in the rate limiting queue 144 is transmitted to the LAN side communication unit 32 at a transmission rate with the rate limiting value LR calculated by the limiting rate calculation processing unit 145b as the upper limit ( In other words, it transmits at a lower priority).

  Next, the limit rate calculation processing unit 145b reads the AC value and the DC value stored in the rate information storage unit 24, and calculates the rate limit value LR based on the read value. Note that the calculated LR value is stored in a memory inside the limit rate calculation processing unit 145b or output to a file or the like in a state that can be referred to by the packet transmission processing unit 142b.

  Next, the QoS target setting processing unit 16b responds to the request received from the data transmitting / receiving apparatus 400 via the packet transfer processing unit 11, and the QoS target storage unit 22, the queue assignment information storage unit 23, and the rate information storage unit 24. Predetermined data (for example, HTML data) constituting the QoS target setting screens 261 and 262 which are user interfaces for updating the data stored in the data transmission / reception device 400 are transmitted to the data transmission / reception apparatus 400. That is, the QoS target setting processing unit 16b includes a general Web server function. The QoS target setting screen 262 is a screen on which the user of the data transmitting / receiving apparatus 400 can set the AC value and the DC value in the HGW 101b. The QoS target setting screen 262 will be described later.

  Then, the QoS target setting processing unit 16b updates the data stored in the QoS target storage unit 22 based on the content input by the user of the data transmitting / receiving apparatus 400 on the QoS target setting screen 261. In addition, the data stored in the rate information storage unit 24 is updated based on the contents input by the user of the data transmitting / receiving apparatus 400 on the QoS target setting screen 262.

  In addition, when it is necessary to update the display of the QoS target setting screen 261 or the QoS target setting screen 262 when the update process is performed, predetermined data (for example, HTML data) constituting them is transferred to the data transmitting / receiving device. 400.

  Further, the QoS target setting processing unit 16 updates the display of any of the QoS target setting screens 261 and 262 in response to the notification that the QoS target update processing unit 17 has created a new entry in the QoS target storage unit 22. In order to do this, predetermined data (for example, HTML data) constituting the QoS target setting screens 261 and 262 is transmitted to the data transmitting / receiving apparatus 400.

(Processing flow when HGW receives a packet)
Since the flow of processing when the HGW 101b receives a packet is the same as the flow of processing when the HGW 101a receives a packet described with reference to FIG. 6, the description thereof is omitted here. However, the difference is that the operation subject performing the transmission rate control processing in step S505 is the transmission rate control processing unit 14b.

  Also, the flow of the transmission rate control processing performed by the transmission rate control processing unit 14b is the same as the flow of the transmission rate control processing performed by the transmission rate control processing unit 14 described with reference to FIG. Omitted. However, the difference is that in step S910, the packet transmission processing unit 142 limits the transmission rate to be equal to or less than the rate limit value LR calculated by the limit rate calculation processing unit 145b.

(QoS target setting screen)
Next, the QoS target setting screens 261 and 262 will be described. The screen example of the QoS target setting screen 261 is the same as the screen example of the QoS target setting screen 161 shown in FIG. However, the QoS target setting screen 261 is different in that the transition to the QoS target setting screen 262 is made by pressing the “detailed setting” button B1.

  Next, a screen example of the QoS target setting screen 262 will be described with reference to FIG. FIG. 13 is a schematic diagram illustrating a screen example of the QoS target setting screen 262. This screen is provided by the QoS target setting processing unit 16b in response to a request from the data transmission / reception device 400, and is accessed by the user of the data transmission / reception device 400 using a Web browser or the like.

  Although it is assumed that the screen changes to this screen when the “detailed setting” button B1 is pressed on the QoS target setting screen 261, the present invention is not limited to this, and settings related to the routing function and the like of the HGW 101b are made. A link for moving to this screen may be provided on the screen for performing this operation (a general router setting screen), or the user may directly input the URL of this screen into the Web browser. Further, an input / output device may be connected to the HGW 101b so that the setting can be performed from the connected input / output device.

  In this screen, as shown in the figure, (1) the line capacity AC of the access network 702, (2) the current transmission rate of the priority data flow and the total value of the transmission rate, and (3) necessary for transmission of the priority data flow The total value DC of various transmission rates is displayed.

  Regarding (1) and (3) above, the contents stored in the rate information storage unit 24 are read and displayed.

  For (2) above, the current transmission rate of the data flow of the service whose value in the “priority necessity information” column of the QoS target storage unit 22 is set to “necessary” is measured and displayed. For example, the average rate for the past 1 second and the past instantaneous maximum rate are measured and displayed. Since the transmission rate changes sequentially, it is re-measured at a predetermined period and redisplayed. Instead of redisplaying at a predetermined cycle, the transmission rate calculated when the QoS target setting screen 262 is displayed may be continuously displayed.

  In the illustrated example, the video data flow of the video distribution service A and the video data flow of the video distribution service A are data flows that are preferentially transmitted, and the current transmission rates are 9.5 Mbps and 14.0 Mbps, respectively. And that their total value is 23.5 Mbps.

  Instead of displaying the current transmission rate of the priority data flow, the current transmission rate of the priority data flow for each data transmitting / receiving apparatus 400 may be displayed.

  The AC value can be input by the user through the input field N6, and the DC value can be input by the user through the input field N7. The input fields N6 and N7 are assumed to be text boxes, but are not particularly limited. The user inputs a DC value in the input field N7 with reference to the current transmission rate of the priority data flow and the total value of the transmission rates.

  When an AC value is input in the input field N6, the QoS target setting processing unit 16b updates the AC value stored in the rate information storage unit 24. When a DC value is input in the input field N7, the QoS target setting processing unit 16b updates the DC value stored in the rate information storage unit 24.

  The update timing is not limited to when the user inputs in the input fields N6 and N7, and may be when the “Determine” button B6 on the QoS target setting screen 262 is pressed. .

(Transition of transmission bandwidth used by data flow in access network)
Next, with reference to FIG. 14, the use state of the transmission band in the access network 702 when the transmission rate of the data flow sent to the home network 501 by the HGW 101b is limited will be described. FIG. 14 is a schematic diagram illustrating an example of temporal transition of the transmission band used in the access network 702 when the transmission rate of the data flow transmitted to the home network 501 is limited by the HGW 101b.

  Note that the line capacity of the access network 702 in this example is 70 Mbps, and the line capacity of the Internet 701 and the home network 501 is 100 Mbps. Further, it is assumed that the QoS target storage unit 22 stores the data shown in Table 2. Then, the FTP data flow from the FTP server 605, the video data flow from the video distribution server 602 to the video distribution service A, the video data flow from the video distribution server 603 to the video distribution service B, and the video distribution service C from the video distribution server 604 to each other. Video data flows are transmitted respectively.

  Since the user wants to receive the video distribution service A (required transmission rate is 10 Mbps) and the video distribution service B (required transmission rate is 15 Mbps) preferentially, the total value (25 Mbps) of these transmission rates is sent to the HGW 101b It is assumed that it has been registered in advance. In addition, it is assumed that the user has registered in advance the line capacity value (70 Mbps) of the access network 702 in the HGW 101b. Therefore, in this case, the rate limit value LR is always 45 Mbps (= 70 Mbps−25 Mbps). It should be noted that the user acquires the necessary transmission rate of the data flow of each service by examining the manual of the data transmitting / receiving apparatus 400, the website, or the like.

  First, it is assumed that only the FTP data flow is transmitted until time T21. At this time, since the entry having the domain name of the FTP server 605 is not stored in the queue allocation information storage unit 23, the packet distribution processing unit 141 stores the packet of the FTP data flow in the rate limiting queue 144. However, since there is no data flow stored in the rate non-limit queue 143 until time T21, the rate limit mode is not set.

  Therefore, the packet transmission processing unit 142b transmits the FTP data flow packet stored in the rate limiting queue 144 without limiting the transmission rate. As a result, the packet of the FTP data flow is transmitted so as to make maximum use of 100 Mbps, which is the line capacity of the home network 501.

  Therefore, the transmission rate of the FTP data flow in the access network 702 at this point is 70 Mbps, which is the line capacity of the access network 702, as illustrated. As described with reference to FIG. 11, the transmission rate of the FTP data flow slightly increases and decreases with the passage of time (the concave portion of the graph shown in FIG. 14). The range of increase / decrease is a constant time width and a constant rate width, but this is for simplification of explanation.

  Next, it is assumed that transmission of the video data flow of the video distribution service A is started from time T21. Since the entry having the domain name of the video distribution server 602 is stored in the queue assignment information storage unit 23 and the value of the “assignment queue” of the entry is “rate unrestricted”, the packet distribution processing unit 141 Stores the packet of the video data flow of the video distribution service A in the rate unrestricted queue 143.

  Therefore, since the rate limit mode is set from this point, the packet transmission processing unit 142b sets the packet of the FTP data flow stored in the rate limit queue 144 so that the transmission rate is 45 Mbps or less which is the rate limit value LR. Send while restricting.

  Since the video data flow of the video distribution service A (required transmission rate is 10 Mbps) is transmitted at the remaining 25 Mbps, it is possible to suppress the occurrence of transmission delay of the video data flow.

  In FIG. 14, it is described that the transmission rate of the video data flow is immediately transmitted at time T21. However, originally, the transmission rate of the video data flow of the video distribution service A is from time T21. Rise gradually. However, in the same figure, description is abbreviate | omitted for the simplification of description.

  Next, it is assumed that transmission of the video data flow of the video distribution service B is started from time T22. Since the entry having the domain name of the video distribution server 603 is stored in the queue assignment information storage unit 23 and the value of the “assignment queue” of the entry is “rate unrestricted”, the packet distribution processing unit 141 Stores the packet of the video data flow of the video distribution service B in the rate unrestricted queue 143. Therefore, the video data flows of the video distribution service A and the video distribution service B are stored in the rate non-limitation queue 143 from time T22.

  Therefore, the rate limiting mode is continuously maintained, and the packet transmission processing unit 142b limits the packet of the FTP data flow stored in the rate limiting queue 144 so that the transmission rate is 45 Mbps or less which is the rate limiting value LR. While sending.

  Then, at the remaining 25 Mbps, the video data flow of the video distribution service A (required transmission rate is 10 Mbps) and the video data flow of the video distribution service B (required transmission rate is 15 Mbps) stored in the rate unrestricted queue 143 are transmitted. Therefore, it is possible to suppress the occurrence of transmission delay of the video data flow.

  Note that even in the period from time T22 to time T23, there may be a vacancy in the transmission band of the video data flow. The reason why such a vacancy is generated is that the “required transmission rate” stored in the QoS target storage unit 22 is usually set to be larger than the actually required transmission rate. However, since the transmission rate of the FTP data flow is limited to 45 Mbps, even if there is a vacant transmission band as described above, the FTP data flow is not transmitted using the vacant space.

  Next, it is assumed that transmission of the video data flow of the video distribution service C is started from time T23. Since the entry having the domain name of the video distribution server 603 is stored in the queue assignment information storage unit 23 and the value of the “assignment queue” of the entry is “rate limiting”, the packet distribution processing unit 141 The video data flow packet of the video distribution service C is stored in the rate limiting queue 144. That is, from time T23, the FTP data flow and the video data flow of the video distribution service C are stored in the rate limiting queue 144, and the video data flows of the video distribution service A and the video distribution service B are stored in the rate non-limit queue. 143. The rate limit value LR remains unchanged at 45 Mbps.

  Therefore, the total transmission rate of the FTP data flow and the video data flow of the video distribution service C is 45 Mbps. Since the video data flow of the video distribution service A (required transmission rate is 10 Mbps) and the video data flow of the video distribution service B (required transmission rate is 15 Mbps) are transmitted at the remaining 25 Mbps, the video distribution service A and the video With respect to the video data flow of the distribution service B, it is possible to suppress the occurrence of transmission delay and the like.

  In this case, the video data flow of the video distribution service C uses the transmission band with the same priority as the FTP data flow. However, since it is not always possible to secure a sufficient transmission band so that transmission delay and jitter do not occur, in the data transmitting / receiving apparatus 400 that receives the video data flow of the video distribution service C, there is a possibility that the reproduction of video and the like may be disturbed. is there.

  Next, when transmission of the video data flow of the video distribution service C is completed at time T24, the packet transmission processing unit 142b performs the FTP data flow stored in the rate limiting queue 144 as in the period from time T22 to T23. Of the video distribution service A and the video data of the video distribution service B stored in the rate-unrestricted queue 143 at the remaining 25 Mbps with the transmission rate limited to 45 Mbps or less. Send the flow.

  Next, when transmission of the video data flow of the video distribution service B is completed at time T25, the packet transmission processing unit 142b performs the FTP data flow stored in the rate limiting queue 144 as in the period from time T21 to T22. And the video data flow of the video distribution service A stored in the rate unrestricted queue 143 is transmitted at the remaining 25 Mbps.

  Finally, when transmission of the video data flow of the video distribution service A is completed at time T26, the packet transmission processing unit 142b transmits the packet of the FTP data flow stored in the rate limiting queue 144 as before time T21. The transmission rate is limited so that the transmission rate is 45 Mbps or less.

  In the above description, it is assumed that the FTP data flow, the video data flow of the video distribution service A, the video data flow of the video distribution service B, and the video data flow of the video distribution service C are transmitted one by one. This is the same even when a plurality of the same video data flows are transmitted. For example, even when two video data flows of the video distribution service A are transmitted when the FTP data flow is transmitted, the packet transmission processing unit 142 stores the FTP data stored in the rate limiting queue 144. Flow packets are sent with a limit of 45 Mbps.

[Additional Notes]
(Transmission rate of preferentially transmitted data flow)
A video data flow or the like is not transmitted at a constant transmission rate, and the transmission rate may increase or decrease temporarily (instantaneously). When the transmission rate increases temporarily (instantaneously), the transmission band that has been secured in advance may be exceeded. In this case, transmission delay or packet loss occurs.

  In order to solve such a problem, it is desirable to set the value of the “required transmission rate” column of the QoS target storage unit 22 to a value larger than the actually required transmission rate. For example, when the HGW 101 is shipped from the factory, it is conceivable that the vendor of the HGW 101 stores a value that is several percent higher than the transmission rate that is actually required. Further, for all data flows, a value that is 1 Mbps larger than the actually required transmission rate may be stored.

  In addition, the user may set a value larger than the actually required transmission rate using the QoS target setting screen 161 (162). In order to prompt the user to make such a setting, it is desirable that this is described in the manual of the HGW 101 or that this is displayed on the QoS target setting screen 161 (162). Further, the HGW 101 may convert the value set by the user into a value about several percent larger than the value.

(Transmission according to the priority given to the packet)
When the server 600 transmits a packet given “priority”, the HGW 101 may change the order of sending the packet to the home network 501 according to the priority. Note that the priority of a packet transmitted on the IP network is a value represented by the upper 3 bits of a field called DSCP in the second byte from the head of the IPv4 (IP Version 4) header, or IPv6 (IP Version 6) A value represented by the upper 3 bits of a field called DSCP included in the traffic class field of the header.

  For example, in each of the above-described embodiments, the video data packet of the video distribution service B, which is set not to be transmitted preferentially, is stored in the rate limiting queue 144 in the same manner as the FTP data packet. Are sent from the rate limit queue 144 with the same priority as However, if a higher priority is given to the video data packet of the video distribution service B than the FTP data packet, the video data may be sent from the rate limiting queue 144 with priority over the FTP data packet. Even in this case, no transmission rate exceeding the rate limit value LR is transmitted. That is, the priority remains lower than the video data packets of the video distribution service A and the video distribution service C that are set to be preferentially transmitted.

  Further, for example, when different priorities are assigned to the video data packet of the video distribution service A and the video data packet of the video distribution service C, which are set to be preferentially transmitted, it is higher. Video data packets to which priority is given may be preferentially transmitted from the rate non-limit queue 143. In order to limit the transmission rate of the non-priority data flow to the rate limit value LR or less so that a sufficient transmission band for transmitting the priority data flow can be secured, usually, the video data of the video distribution service A and the video distribution service C is used. Even if a priority is given to each of the packets, any video data packet can be transmitted without causing a transmission delay or the like. However, by performing packet transmission taking priority into account, if the setting of the rate limit value LR of the non-priority data flow is insufficient (if the transmission band allocated to the priority data flow is insufficient, the user setting Even if there is a deficiency in the data), there is an advantage that at least only packets with high priority can be transmitted without causing transmission delay or the like as much as possible.

(Restriction on the number of data flows stored in an unrestricted queue)
If packets of all priority data flows are stored in the rate non-limitation queue 143 and the stored packets are sent to the home network 501, a transmission band may be insufficient. Therefore, the number of data flows to which packets stored in the rate non-limit queue 143 belong may be limited.

  For example, when eight video data flows (10 Mbps) of the video distribution service A are transmitted, packets belonging to all the data flows are stored in the rate unrestricted queue 143, and the stored packets are stored in the home network 501. When the data is transmitted, the line capacity of the home network 501 does not exceed 70 Mpbs, which is the line capacity of the access network 702, and as a result, all the data transmission / reception apparatuses 400 that receive each data flow access. The transmission band in the network 702 is insufficient, and the reproduction of video and audio is disturbed. Therefore, by limiting the data flows stored in the rate non-limit queue 143 to, for example, seven, the transmission bandwidth of the data flows for the seven can be ensured. However, in this case, since the transmission rate that can be transmitted from the rate limiting queue 144 is 0 Mbps, only the packet stored in the rate non-limiting queue 143 is actually transmitted to the home network 501.

  Also, if the transmission bandwidth of each video data flow is temporarily increased, the transmission bandwidth becomes insufficient, so the data flow stored in the rate non-limit queue 143 is further limited to, for example, 6 lines. May be.

  Further, it is conceivable that the data flow is stored in the rate non-limit queue 143 in the order in which the transmission is started, and is stored in the rate limit queue 144 after reaching a predetermined specified number.

  Further, when transmission of a data flow stored in the rate non-limit queue 143 is stopped, if there is a data flow stored in the rate limit queue 144 even though it is a QoS target flow, its storage destination May be changed to the rate non-limit queue 143.

(Configuration of DNS processing unit)
In the above-described embodiment, the HGW 101 includes the DNS processing unit 12. However, the present invention is not limited to this. The DNS processing unit 12 is not necessarily provided in the HGW 101 and may be configured to be communicable with the HGW 101 as an external device (for example, via Ethernet).

(Destination of DNS inquiry message)
In the above-described embodiment, the data transmission / reception device 400 such as the STB 401 sets the IP address of the video distribution server 603 to the HGW 101 as a default DNS server as a process of starting reception of video content (reception start process). Although the DNS inquiry message to be inquired is transmitted and the HGW 101 performs the queue assignment information generation processing based on the domain name included in the DNS response message with respect to the DNS inquiry message, the present invention is not limited to this. Queue assignment information generation processing may be performed based on a DNS response message corresponding to a DNS inquiry message for another server to access before starting reception.

  For example, the data transmission / reception device 400 transmits a DNS inquiry message for inquiring the IP address of the portal server, and the HGW 101 performs queue assignment information generation processing based on the domain name included in the DNS response message for the DNS inquiry message. Also good. Here, the portal server is assumed to be, for example, a server that provides a portal site to be accessed first for the user to enjoy the video distribution service. The portal site is assumed to be capable of displaying thumbnails of video content provided by the video distribution service and allowing the user to select video content.

  The domain name of the video distribution server may be modified such as addition, deletion, or change for convenience of the service provider, but the domain name of the portal server is relatively rarely modified. In a device such as the data transmission / reception device 400, the domain name of the portal server is stored at the time of factory shipment, and when the power is turned on, the domain name is accessed and the portal site is first presented to the user, from which the content is displayed. Generally, it is configured to cause selection. When the domain name of the portal server is changed, when the data transmission / reception apparatus 400 is turned on, the portal site is not displayed and an error is displayed, and the convenience for the user is significantly reduced. If the domain name of the portal server registered in the data transmission / reception device 400 is changed by updating the data transmission / reception device 400 or the like, it is possible to cope with it, but not all users will perform the update work. However, it is difficult to change the domain name of the portal server. On the other hand, since the data transmission / reception apparatus 400 acquires the domain name of the video distribution server when the user selects content on the portal site, it does not cause a big problem.

  When the domain name of the video distribution server is changed, if the changed domain name is not stored in the QoS target storage unit 22, transmission is performed from the video distribution server having the changed domain name. The queue allocation information generation process is not executed for the packet to be processed. Accordingly, the domain name of the portal server that is rarely modified is set as the value of each “domain name” column of the QoS target storage unit 22, the queue allocation information storage unit 23, and the server address storage unit 21, and the queue allocation information generation processing is performed. You may make it perform.

  Since the IP address of the portal server and the IP address of the video distribution server that actually transmits the video data packet are different, the packet matching the IP address of the portal server and the IP address of the STB is set to be preferentially transmitted. Then, the video data packet transmitted from the video distribution server to the STB is not preferentially transmitted. In this case, it is conceivable to determine whether or not to preferentially transmit using only the IP address of the STB. However, in this case, since all packets received (or transmitted) by the STB are preferentially transmitted, priority is given to packets that do not need to be preferentially transmitted (for example, Web data received by the STB). As a result, the overall QoS control efficiency is reduced.

  In addition to the above, the embodiment can be expressed as follows.

  [1] A communication control device according to the present invention is a communication control device for transferring a flow transmitted from a device belonging to a first network to a device belonging to a second network. A transmission rate control means for controlling a transmission rate in the first network, further comprising a QoS flow determination means for determining whether or not the flow to be transferred is a flow that requires QoS guarantee; Thus, the transmission rate in the first network may be lowered by the transmission rate control means for a flow that is not determined to be a flow that requires QoS guarantee.

  [2] Further, in the communication control apparatus according to the present invention, the transmission rate control means may reduce a rate at which the TCP flow is transmitted to the second network.

  [3] Further, in the communication control apparatus according to the present invention, the QoS flow determination means has a QoS target storage means for storing a domain name to which a transmission apparatus of a flow requiring a QoS guarantee belongs, and analyzes a DNS response packet. A domain name extraction unit that extracts a domain name of a DNS inquiry target, and whether or not the domain name stored in the QoS target storage unit matches the domain name extracted by the domain name extraction unit It may be determined whether or not QoS guarantee is necessary.

  Finally, the main control unit 10 may be realized by software using a CPU (Central Processing Unit) or may be configured by hardware logic. When implemented by software, the HGW 101 stores a CPU that executes instructions of a control program that implements each function, a ROM that stores the program, a RAM that expands the program, a memory that stores the program and various data, and the like. A device (recording medium) is provided. An object of the present invention is to provide a recording medium in which a program code (execution format program, intermediate code program, source program) of a control program of the HGW 101 that is software for realizing the above-described functions is recorded on the HGW 101. This can also be achieved by reading and executing the program code recorded in the recording medium by the computer (or CPU or MPU (Micro Processing Unit)) in the HGW 101.

  Examples of the recording medium include a tape system such as a magnetic tape and a cassette tape, a magnetic disk such as a floppy (registered trademark) disk / hard disk, and an optical disk such as a CD-ROM / MO / MD / DVD / CD-R. Card system such as IC card, IC card (including memory card) / optical card, or semiconductor memory system such as mask ROM / EPROM / EEPROM / flash ROM.

  Alternatively, the HGW 101 may be configured to be connectable to a communication network, and the program code may be supplied via the communication network. The communication network is not particularly limited. For example, the Internet, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, satellite communication. A net or the like is available. Also, the transmission medium constituting the communication network is not particularly limited, and for example, an infrared ray such as IrDA, Bluetooth (Bluetooth) (IEEE1394 cable, USB cable, power line carrier, cable TV line, telephone line, ADSL line, etc.) (Registered trademark), IEEE802.11 radio, HDR, mobile phone network, satellite line, terrestrial digital network, and the like can also be used. The present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The present invention can be suitably used for a communication control apparatus that controls transmission of communication packets in a communication network. In particular, it can be suitably used for an HGW that connects a home network and an access network.

11 packet transfer processing unit 12 DNS processing unit (domain name / address extraction means, address acquisition means)
13 Queue allocation information generation processing unit (transmission control information generation means, first priority necessity information acquisition means)
14 Transmission rate control processing unit 14b Transmission rate control processing unit 16 QoS target setting processing unit (priority necessity information setting means)
16b QoS target setting processing unit (priority necessity information setting means)
21 Server address storage unit 22 QoS target storage unit (second storage unit)
23 Queue allocation information storage unit (first storage unit)
24 Rate information storage unit (third storage unit)
100 communication control device 101 HGW (communication control device)
101a HGW (communication control device)
101b HGW (communication control device)
141 Packet distribution processing unit (source address / destination address extraction means, second priority necessity information acquisition means, communication packet storage means)
142 packet transmission processing unit (data flow transmission control means)
142b Packet transmission processing unit (data flow transmission control means)
143 Rate unrestricted queue (priority packet holding unit)
144 Rate limit queue 145 Limit rate calculation processing unit (priority transmission rate calculation means, transmission rate calculation means)
145b Limit rate calculation processing unit (priority transmission rate calculation means, transmission rate calculation means)
400 Data transmitter / receiver (data receiver)
401 STB (data receiving device)
402 STB (data receiving device)
403 STB (data receiving device)
404 PC (data receiving device)
500 First communication network 501 Home network (first communication network)
600 server (data transmission device)
601 DNS server 602 Video distribution server (data transmission device)
603 Video distribution server (data transmission device)
604 Video distribution server (data transmission device)
605 FTP server (data transmission device)
700 Second communication network 702 Access network (second communication network)
703 Base station 900 communication control system LR rate limit value (limit value)

Claims (10)

A data flow composed of a plurality of communication packets connected to the first communication network to which the data receiving device is connected and the second communication network to which the data transmitting device is connected, and transmitted from the data transmitting device to the data receiving device. A communication control device for controlling transmission to the first communication network,
Each communication packet constituting the data flow includes a communication address of the data transmission device that is a transmission source of the communication packet, and a communication address of the data reception device that is a transmission destination of the communication packet,
A first storage unit that stores the communication address of the data transmission device and the communication address of the data reception device in association with each other;
A source address / destination address extracting means for extracting the source communication address and the destination communication address from the communication packet constituting the data flow;
When the combination of the communication address of the transmission source and the communication address of the transmission destination extracted by the transmission source address / destination address extraction means is not stored in the first storage unit, the data transmission device A communication control apparatus comprising: a data flow transmission control unit configured to transmit the data flow to be transmitted to the data receiving apparatus to the first communication network with a reduced priority.   2. The communication control apparatus according to claim 1, wherein the data flow transmission control means further transmits the data flow transmitted at a lower priority at a transmission rate that does not exceed a predetermined limit value. A second storage unit that stores in advance, for each data flow, a transmission rate necessary for transmitting the data flow that is a target to be transmitted preferentially;
A third storage unit for previously storing the line capacity of the second communication network;
A priority packet holding unit for temporarily storing the communication packet of the data flow to be preferentially transmitted;
When the combination of the source communication address and the destination communication address extracted by the source address / destination address extracting means is stored in the first storage unit, the communication of the data flow Communication packet storage means for storing the packet in the priority packet holding unit;
The transmission rate of each of the data flows composed of the communication packets stored in the priority packet holding unit is acquired from the second storage unit, and the total value of all the acquired transmission rates is calculated. Priority transmission rate calculation means;
A transmission rate calculating means for calculating the limit value by subtracting the total value calculated by the transmission rate calculating means from the line capacity of the second communication network stored in the third storage unit; The communication control apparatus according to claim 2. The data receiving device transmits a first request for requesting a communication address of the data transmitting device and, based on the communication address of the data transmitting device included in a response to the first request, to the data transmitting device. A second request for requesting the data flow,
The data transmission device belongs to a domain, and transmits the data flow as a response to the second request to the data reception device,
The first request includes a domain name of a domain to which the data transmitting device belongs and a communication address of the data receiving device,
The first storage unit is associated with the communication address of the data transmission device associated with the communication address of the data reception device, and further stores the domain name of the data transmission device,
The second storage unit stores a transmission rate necessary for transmitting the data flow to be transmitted with priority in association with a domain name of the data transmitting apparatus that transmits the data flow. There,
A domain name / address extracting means for extracting the domain name of the data transmitting device and the communication address of the data receiving device from the response;
Address acquisition means for acquiring the communication address of the data transmission device associated with the domain name of the data transmission device extracted by the domain name / address extraction means;
When the domain name of the data transmission device extracted by the domain name / address extraction unit is stored in the second storage unit, the communication address of the data transmission device acquired by the address acquisition unit and the domain name A transmission control information generating unit that associates the communication address of the data receiving device extracted by the address extracting unit and stores the communication address in the first storage unit;
The priority transmission rate calculation means acquires the domain name of the data transmission device associated with the communication address of the transmission source of the communication packet stored in the priority packet holding unit from the first storage unit. In addition, for each acquired domain name, the transmission rate associated with the acquired domain name is acquired from the second storage unit, and a total value of all the acquired transmission rates is calculated. The communication control device according to claim 3. The second storage unit stores a domain name of the data transmission device that transmits a data flow that is not a target to be transmitted with a domain name of the data transmission device that transmits a data flow that is a target to be transmitted with priority. Further, priority necessity information indicating whether or not the data flow transmitted by the data transmission device having the domain name needs to be transmitted with priority is stored in association with the domain name. ,
The first storage unit stores the priority necessity information in association with the communication address of the data transmission apparatus associated with the communication address of the data reception apparatus,
A first priority necessity information acquisition unit that acquires the priority necessity information associated with the domain name of the data transmission device extracted by the domain name / address extraction unit from the second storage unit;
The transmission control information generating means includes a communication address of the data transmitting apparatus acquired by the address acquiring means, a communication address of the data receiving apparatus extracted by the domain name / address extracting means, and the domain name / address extracting means. The domain name of the data transmission device extracted by the first priority necessity information acquisition means is associated with the priority necessity information and stored in the first storage unit,
The data flow transmission control means further includes:
A second priority necessity information acquisition unit that acquires the priority necessity information associated with the transmission source communication address extracted by the transmission source address / destination address extraction unit from the first storage unit;
When the priority necessity information acquired by the second priority necessity information acquisition means indicates that the data flow does not need to be transmitted with priority, the data transmitting apparatus transmits to the data receiving apparatus. The communication control apparatus according to claim 4, wherein the data flow to be transmitted is transmitted to the first communication network at a lower priority.   A user interface that can be input in association with the domain name of the data transmitting device and the priority necessity information is presented to the data receiving device, and the domain name of the data transmitting device input through the user interface 6. The communication control apparatus according to claim 5, further comprising priority necessity information setting means for associating with the necessity information for priority and storing the information in the second storage unit.   The data flow to be transmitted to the first communication network with a reduced priority is transmitted by the data transmission device using a communication protocol in which the transmission amount of the communication packet can be controlled by the data transmission device. The communication control device according to claim 1, wherein the communication control device transmits the data to the data receiving device. Connected to the first communication network to which the data receiving apparatus is connected and the second communication network to which the data transmitting apparatus is connected, the communication address of the data transmitting apparatus and the communication address of the data receiving apparatus are stored in advance in association with each other. A control method of a communication control apparatus, comprising a first storage unit, for controlling transmission of a data flow composed of a plurality of communication packets transmitted from the data transmission apparatus to the data reception apparatus to the first communication network. There,
Each communication packet constituting the data flow includes a communication address of the data transmission device that is a transmission source of the communication packet, and a communication address of the data reception device that is a transmission destination of the communication packet,
A source address / destination address extraction step for extracting the source communication address and the destination communication address from the communication packet constituting the data flow;
When the combination of the source communication address and the destination communication address extracted in the source address / destination address extraction step is not stored in the first storage unit, the data transmitting device A control method for a communication control device, comprising: a data flow transmission control step for transmitting the data flow to be transmitted to the data receiving device to the first communication network with a reduced priority.   A control program for operating a computer included in the communication control device according to claim 1, wherein the control program causes the computer to function as each unit.   A computer-readable recording medium on which the control program according to claim 9 is recorded.

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