KR101300906B1 - Router for bypassing packet based on bypass time - Google Patents

Abstract

The present invention relates to a packet router, and more specifically, to synchronize a standard time of routers existing in a communication network with each other, and to set a packet bypass time of each router based on a reception delay time between each router in a packet routing path. It relates to a router that forwards packets received at the bypass time to the next hop router without a separate packet process.

Description

Router for bypassing packet based on bypass time

The present invention relates to a packet router, and more specifically, to synchronize a standard time of routers existing in a communication network with each other, and to set a packet bypass time of each router based on a reception delay time between each router in a packet routing path. It relates to a router that forwards packets received at the bypass time to the next hop router without a separate packet process.

The quality of service (QoS) of a communication network is determined by factors of timeliness, bandwidth, and reliability. Among the factors that determine the quality of service of a communication network, bandwidth and reliability can be overcome by increasing the bandwidth or improving the reliability performance of communication equipment as a cost-proportional factor. The time necessary for forwarding to a router is important, especially for seamless playback of audio or video in a real-time streaming service such as audio or video. Here, the timeliness is determined by the processing of the router's queuing mechanism, buffering structure, and the like, and it takes time for the router to forward the packet to the next hop router, including queuing or buffering the packet.

In order to improve service quality in end-to-end real-time communication service, an integrated service (Intserv, Integrated Service) model has been proposed and used. The integrated service model uses a resource reservation protocol (RSVP) signaling protocol, which is a resource reservation protocol, to guarantee quality of service on a traffic flow basis. RSVP is used to reserve resources and forward packets before traffic is transmitted, ensuring the quality of the real-time streaming service.

In the integrated service model, the quality of service is satisfied by forwarding packets using reserved transmission resources. However, in the case of end-to-end real-time packet forwarding service, packet forwarding time is delayed due to packet processing delay at each router in the packet routing path. This causes a failure to efficiently use the limited communication bandwidth.

The present invention is to solve the problems caused by the packet forwarding of the end-to-end real-time streaming mentioned above, the object of the present invention is to set the packet bypass time in each router and to receive the packet received at the packet bypass time It is to provide a router that forwards packets by passing them to the next hop without delaying packet processing time.

Another object of the present invention is to synchronize a standard time with a master router existing in a communication network, to set a packet bypass time based on the synchronized standard time, and to process a packet received at the set packet bypass time. It provides a router that forwards packets by forwarding to the next hop without delay.

Another object of the present invention is to classify packets that are subject to packet bypass based on the packet size from various packets received at the packet bypass time set by each router, thereby to directly forward packets to the next hop without packet processing delay. It is to provide a forwarding router.

Another object of the present invention is to provide a router capable of optimizing packet bypass time by transmitting and receiving a plurality of synchronization messages and synchronization configuration messages.

In order to achieve the object of the present invention, a router according to the present invention is configured to include a standard time setting unit for synchronizing a standard time with a master router of a communication network, and packet reception delay time information of a previous hop router in a packet routing path. A packet bypass manager that repeatedly generates and sends a request message to a next hop router and sets and manages a packet bypass time based on the packet bypass time included in the configuration response message repeatedly received in response to the configuration request message; Bypass buffer section for storing packets for bypass forwarding to the next hop of the routing path; Bypass packets received at the packet bypass time to the bypass buffer section to bypass the bypass buffer section to the next hop router without packet processing. Including packet forwarding to control forwarding .

Here, the communication network uses an integrated service model that transmits and receives packets using a resource reservation protocol. The packet is a real-time streaming packet such as audio or video, and the standard time setting unit uses the PTP (Precision Time Protocol) method of the IEEE 1588 standard. Characterized in that the standard time setting.

Preferably, the packet forwarding unit may include a bypass time determining unit that determines whether a packet reception time is received at a packet bypass time based on a packet reception time, and a size of the received packet when the packet is received at a packet bypass time. And determining a size of the bypass packet based on the size of the received packet.

Preferably, the packet bypass management unit responds to the configuration request message generation unit repeatedly generating and transmitting a configuration request message including packet reception delay time information with the previous hop router in the packet routing path to the next hop router. And a bypass time setting unit for setting a packet bypass time based on the packet bypass time included in the repeated response message.

Herein, the setup request message and the setup response message are transmitted and received as many times as the threshold setting times.

Preferably, the setting request message generation unit includes a delay time calculating unit for calculating a packet reception delay time from a difference between the packet reception time of the previous hop router and the standard time of the router in the packet routing path, and a setting including the calculated packet reception delay time information. And a message generator for generating a request message.

The router according to the present invention has various effects as follows.

First, the router according to the present invention sets a packet bypass time and forwards a packet received at the set packet bypass time to the next hop, so that each router in the packet routing path can forward the packet without delay in packet processing time. have.

Second, the router according to the present invention synchronizes the standard time with the master router present in the communication network and sets the packet bypass time based on the synchronized standard time, thereby accurately and easily setting the standard time of each router in the packet routing path. Synchronized and based on the synchronized standard time, packets received at packet bypass time can be forwarded correctly to the next hop.

Third, the router according to the present invention determines the packet target to bypass based on the set packet bypass time and the set packet size, so that the next hop without packet processing delay among the packets received at the set packet bypass time. As a result, packets to be forwarded can be identified accurately and quickly.

Fourth, the router according to the present invention can optimize the packet bypass time of each router by transmitting and receiving a plurality of synchronization messages and synchronization setting messages to set the packet bypass time.

1 is a diagram illustrating a packet forwarding communication system according to the present invention.
2 is a functional block diagram illustrating a packet bypass forwarding router according to the present invention.
3 is a functional block diagram for explaining the packet forwarding unit 10 according to the present invention in more detail.
4 is a functional block diagram for explaining in more detail the packet bypass management unit according to the present invention.
FIG. 5 is a diagram illustrating a message transmitted and received between each router of a packet routing path in order to set a packet bypass time in the present invention.
6 is a diagram illustrating an example of generating a setting request message according to the present invention.
7 is a view for explaining a first example of a method for calculating a packet bypass time in the packet forwarding method according to the present invention.

Hereinafter, a router according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a packet forwarding communication system according to the present invention.

A plurality of communication terminals 2 and 3 are connected to the network 1. The network 1 transmits and receives data in a packet unit between a plurality of communication terminals 2 and 3 connected to the network 1 in a wired / wireless communication network. The network 1 is equipped with a plurality of routers R for forwarding packets between the plurality of communication terminals 2, 3, and the communication terminal 2 and the communication terminal 3 are routers of the network 1. (R) performs end-to-end communication. All routers R present in the network 1 are synchronized with each other in standard time.

Routers provided in the network (1) are synchronized with each other in standard time by the IEEE 1588 Precision Time Protocol (PTP). The IEEE 1588 PTP precisely measures network equipment in microseconds in a network such as Ethernet. A standard that allows synchronization to be synchronized to ensure that the trigger and event time stamps use the same standard time by synchronizing the local and master clocks of the local device and master device on the network. In the present invention, the standard time of all routers (R) present in the network (1) is synchronized using the IEEE 1588 PTP standard, but various standard time synchronization methods may be used according to the field to which the present invention is applied. Belongs to the range.

Here, the network 1 is a communication bandwidth of a routing path between the communication terminal 2 and the communication terminal 3 before data transmission and reception in order to transmit and receive data between the communication terminal 2 and the communication terminal 3 performing end-to-end communication. It reserves and allocates and operates as an integrated service model for transmitting and receiving data between the communication terminal 2 and the communication terminal 3 through the reserved allocated communication bandwidth.

The data transmitted and received between the communication terminal 2 and the communication terminal 3 through the network 1 is characterized in that the real-time streaming data, such as audio, video.

2 is a functional block diagram illustrating a packet bypass forwarding router according to the present invention.

Referring to FIG. 2, the packet forwarding unit 10 determines whether a packet is received at a set packet bypass time by measuring a reception time of a received packet and comparing the measured reception time with a set packet bypass time. If the packet is not received at the packet bypass time based on the determination result, the received packet is queued and queued through the paths of the classifying unit 20, the waiting buffer unit 30, and the packet scheduler 40. Switch to forward to hop routers. Hereinafter, a path for forwarding a packet not received at the packet bypass time to the next hop router through the paths of the classifying unit 20, the waiting buffer unit 30, and the packet scheduler 40 is generally referred to as a forwarding path. On the other hand, when a packet is received at the packet bypass time, the packet forwarding unit 10 normally controls switching to the bypass buffer unit 60 without switching the packet to the forwarding path. Hereinafter, a path for forwarding a packet received at the packet bypass time to the next hop router through the bypass buffer unit 60 without waiting and queuing processing is referred to as a bypass path.

First, in more detail with respect to the normal forwarding path, the packet forwarding unit 10 classifies the packet not received at the packet bypass time based on the reception time and the packet bypass time of the packet synchronized with the standard time. To provide. The classifier 20 analyzes the packet header and provides the received packet to the standby buffer unit 30 which is separated from each other according to the importance of the packet. Preferably, the standby buffer unit 30 includes a plurality of standby buffer units for classifying and storing packets having the same importance according to the importance of the packets, and the packets are classified into the standby buffer units of the corresponding importance according to the importance. Stored. The packet scheduler 40 extracts the packets stored in the wait buffers having different importances as weights corresponding to the importances, and provides the forwarding queue 50 with the packets extracted at different weights in the wait buffers having different importances. Forward to the next hop router. When forwarding the received packet to the next hop router by the normal forwarding path, the packet header is analyzed and the received packet is stored in the standby buffer unit 30 according to the importance of the packet, and the packet scheduler 40 again stores the packet. According to the importance, it is necessary to go through the steps of extracting different weights and forwarding them to the forwarding queue 50. The processing of forwarding the packets received through each forwarding path from each router to the next hop router is referred to as packet processing. The time taken to perform packet processing is referred to as packet processing time.

On the other hand, in more detail with respect to the bypass path, when the packet forwarding unit 10 receives the packet at the packet bypass time based on the reception time and the packet bypass time of the packet synchronized in the standard time, the normal forwarding path It provides a packet received to the bypass buffer unit 60 directly without going through. The bypass buffer unit 60 stores the packets received from the packet forwarding unit 10 and provides the packets to the forwarding queue 50 according to the forwarding queue state of the forwarding queue 50. Therefore, when forwarding a packet through a bypass path to a next hop router, it is possible to save time required to perform packet processing in a normal forwarding path and to efficiently use limited communication resources.

Here, the packet bypass time of the packet forwarding unit 10 is set through the packet bypass management unit 70. The packet bypass management unit 70 delays packet reception with the previous hop router in the packet routing path before end-to-end data transmission and reception. Generate and send a configuration request message including time information to the next hop router, and configure and manage the packet bypass time based on the packet bypass time included in the configuration response message repeatedly received in response to the configuration request message. . The standard time manager 80 synchronizes the standard time with another router present in the communication network 1, and the packet forwarding unit 10 and the packet bypass manager 70 delay the packet reception based on the synchronized standard time. Calculate the time or set the packet bypass time. Preferably, the standard time setting unit 80 is characterized in that the standard time is synchronized by the IEEE 1588 standard PTP (Precision Time Protocol) method. Since the PTP scheme of the IEEE 1588 standard is a known technique, a detailed description thereof will be omitted.

3 is a functional block diagram for explaining the packet forwarding unit 10 according to the present invention in more detail.

Referring to FIG. 3, the bypass time determiner 11 measures a reception time of a packet received from a previous hop router of a packet routing path, and determines whether a packet is received based on the measured packet reception time and a set packet bypass time. It is determined whether the packet is received at the bypass time. On the other hand, the packet size determination unit 13 determines the size of the packet received at the packet bypass time and determines whether the packet received at the packet bypass time is a packet to be bypassed.

Since the packet forwarding unit 10 receives a packet to be forwarded to the next hop router through the forwarding path in addition to the packet that should be forwarded to the next hop router through the bypass path at the set packet bypass time, On the basis of this, the packet to be forwarded to the bypass path is determined. Secondly, it is determined whether the packet is to be forwarded to the next hop router through the bypass path based on the packet size.

If the reception time of the received packet is not the packet bypass time as a result of the primary determination by the bypass time determining unit 11, the bypass time determining unit 11 provides the received packet to the classifying unit 20. Normally, the packet is forwarded through the forwarding path to the next hop router in the packet routing path. On the other hand, if the reception time of the received packet is the packet bypass time, if the received packet is the bypass target packet as a result of the second determination by the packet size determination unit 13, the packet is provided to the bypass buffer unit 60 and bypassed. Forward the packet through the path to the next hop router in the packet routing path. However, if the received packet is not a bypass target packet as a result of the second determination by the packet size determining unit 13, the packet size determining unit 13 provides the received packet to the classifying unit 20 to route the packet through the normal forwarding path. Forward the packet to the next hop router in the path. In general, a packet that requires timeliness is often a real-time streaming packet of audio or video. Therefore, the size of a real-time streaming packet is set to a certain size, and a packet received at a predetermined size at a packet bypass time is passed through a bypass path. Forwarding control to the next hop router in the packet routing path.

The packet bypass router according to the present invention does not require a separate packet processing time when forwarding a packet through a bypass path, and the packet bypass time of each router is obtained by subtracting the packet processing time from the packet reception delay time of each router. It is possible to use limited resources more efficiently by setting based on and forwarding the received packet at the packet bypass time to the next hop router through the bypass path.

4 is a functional block diagram for explaining in more detail the packet bypass management unit according to the present invention.

Referring to FIG. 4, in more detail, when the delay time calculation unit 71 receives a setup request message from a previous hop router of a packet routing path, the delay time calculator 71 receives a packet between a previous hop router and a current router that receives the setup request message. Calculate the delay time. The setup request message received from the previous hop router stores information about a first reception time at which the previous hop router received the setup request message from the previous hop router of the previous hop router on the packet routing path, and the delay calculation unit 71 ) Calculates a packet reception delay time between the previous hop router and the current router from the difference between the first reception time information and the second reception time information that the setup request message is received by the current router.

The message generator 73 regenerates a setup request message including packet reception delay time information between the previous hop router and the current router and packet reception delay time information between the previous hop router and each router before the previous hop router, The configuration request message regenerated through the packet forwarding unit 10 is forwarded to the next hop router of the packet routing path. Each router in the packet routing path further updates the calculated packet reception delay time information to the setting request message to regenerate the setting request message, and sequentially transmits the regenerated setting request message to the destination router for end-to-end communication.

The bypass time setting unit 75 sets the packet bypass time of the packet forwarding unit 10 based on the setting response message which is sequentially forwarded from the destination router to the source router in the reverse order of the packet routing path. The destination router calculates the packet bypass time of each router based on the packet reception delay time information between each router and the reception delay parameter information of each router stored in the received configuration request message. The packet bypass time information of the router is stored in the configuration response message and forwarded to the source router in the reverse order of the packet routing path.

Preferably, each router located in the packet routing path between the source router and the destination router transmits and receives a plurality of configuration request messages and configuration response messages corresponding to each configuration request message to set an optimized packet bypass time. Each router in the routing path typically forwards the first configuration request message to the next hop router via the routing path, and from the second configuration request message to the next hop router through the bypass path.

FIG. 5 is a diagram illustrating a message transmitted and received between each router of a packet routing path in order to set a packet bypass time in the present invention.

Referring to FIG. 5 in more detail, in order to transmit end-to-end packets from the source terminal S to the destination terminal D, an ingress router (IR) connected to the source terminal S must be first. 1 A setup request message is generated and the generated first setup request message is transmitted to the next hop router CR1 of the packet routing path to the egress router ER to which the destination terminal D is connected. We refer to the ingress router as the source router and the egress router as the destination router.

The first setting request message SM1 generated by the source router stores information about a reception time of a packet transmitted from the source terminal to the destination terminal. The next hop first router CR1 measures the reception time of the first setup request message SM1 based on the standard time, and the packet reception time stored in the first setup request message SM1 and the measured first setup request. The packet first reception delay time between the source router and the next hop first router CR1 is calculated from the reception time of the message SM1. The next hop first router CR1 generates a second setup request message SM2 having the packet first reception delay time information and generates the second setup request message SM2 generated by the next hop second router of the packet routing path. Transmit to (CR2). The second configuration request message SM2 stores packet reception delay time information between the source router and the next hop first router CR1 and reception time information of the first configuration request message. The next hop second router CR2 calculates the packet second reception delay time of the next hop first router and the next hop second router, requests packet first reception delay time information, packet second reception delay time information, and a second setting request. A third setup request message SM3 having the reception time information of the message SM2 is generated and transmitted to the next hop third router of the packet routing path.

In this manner, each router on the packet routing path regenerates a configuration request message including packet reception delay time between each router and reception time information of the configuration request message, and sequentially transmits the configuration request message to the destination router.

When the destination router receives the configuration request message regenerated sequentially at each router from the source router to the destination router, the destination router is based on the packet reception delay time information between each router and the reception delay parameter information at each router. Calculates the packet bypass time and generates a configuration response message (SSM) for setting the calculated packet bypass time as the packet bypass time of each router, and sequentially transmits from the destination router to the source router to each router. . Each router in the packet routing path receiving the configuration response message (SSM) extracts its own packet bypass time information and sets the packet bypass time using the extracted packet bypass time information. In this case, the reception delay parameter is a parameter that configures the time taken to forward the packet received by the previous hop router to receive the packet at the next hop router. electronic delay, serialization delay for serializing a packet on the link, transmission delay for transmitting a packet from a transmission medium, and electronic delay, continuous delay, and transmission delay among packet reception delay times. Except for this, it may be divided into a packet processing delay required for forwarding a packet to a next hop router. Since the electronic delay, continuous delay, and transmission delay are quantitative in each router, the packet processing delay time can be calculated by subtracting the electronic delay, continuous delay, and transmission delay from the packet reception delay time.

The configuration request message and the configuration response message are repeatedly transmitted and received between the source router and the destination router by the set number of times, and the destination router receives a set request message each time after receiving the set request message or the set number of packets of each router. Optimize the packet bypass time by averaging the processing delay time.

6 is a diagram illustrating an example of generating a setting request message according to the present invention.

Referring to an example of generating a setup request message with reference to FIG. 6, the source router IR of the packet routing path generates a first setup request message having a packet reception time T to generate a next hop router CR1 of the packet routing path. To send). The next hop router CR1 extracts packet reception time information from the first setup request message, and extracts the source router IR and the next hop router from the standard time of the next hop message CR1 and the reception time information of the first setup request message. The packet first reception delay time Δt11 between CR1) is calculated. The next hop router CR1 generates a second setup request message including a packet first reception delay time and reception time information of the first setup request message, and transmits the second setup request message to the next hop router CR2 in the packet routing path. The next hop router CR2 extracts the reception time information of the first configuration request message from the second configuration request message, and the next hop router CR1 is extracted from the reception time of the first configuration request message and the reception time of the second configuration request message. The packet second reception delay time [Delta] t12 between the next hop routers CR2 is calculated. The next hop message CR2 generates a third setup request message including a packet first reception delay time, a packet second reception delay time, and a reception time information of the second configuration request message to generate a next hop router CR3 in the packet routing path. To send). In the same way, each router in the packet routing path generates a synchronization message and sequentially sends it to the next hop router to the destination router (ER).

7 is a view for explaining a first example of a method for calculating a packet bypass time in the packet forwarding method according to the present invention.

Referring to FIG. 7, the packet reception delay time information between the routers of the packet routing path is extracted from the received configuration request message (S110). The packet processing delay time of each router is calculated from the extracted packet reception delay time information, the packet reception delay time information and the reception delay parameter information between each router extracted from the previously received configuration request message, and the average value of the packet processing delay time is calculated. To calculate (S120). It is determined whether the number of times of receiving the setting request message is the setting number of times (S130), and when the setting request message is received by the number of setting times, packet by delay of each router is subtracted from the packet receiving delay time of each router minus the average value of the packet processing delay time. The pass time is calculated (S140). Preferably, the packet bypass time of each router may be calculated as in Equation (1) below.

[Equation 1]

Where T _BPi is the packet bypass time of router i, T _delayi is the packet reception delay time of router i, T _APi is the average of the packet processing delay time in router i, and T _Ti is the threshold. It's time.

Meanwhile, the above-described embodiments of the present invention can be written as a program that can be executed in a computer, and can be implemented in a general-purpose digital computer that operates the program using a computer-readable recording medium.

The computer-readable recording medium may be an electrically or magnetic storage medium such as a ROM, a floppy disk, a hard disk, etc., an optical reading medium such as a CD-ROM or a DVD and a carrier wave, , Transmission over the Internet).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1: network 2, 3: communication terminal
10: packet forwarding unit 20: classification unit
11: Bypass time determining unit 13: Packet size determining unit
30: waiting buffer unit 40: packet scheduler
50: forwarding queue 60: bypass buffer unit
70: packet bypass management unit 80: standard time setting unit
71: delay time calculation unit 73: message generation unit
75: bypass time setting section

Claims (8)

A standard time setting unit for synchronizing a standard time with a master router of a communication network;
In the packet routing path, a repeatedly generated setup request message including packet reception delay time information with the previous hop router is transmitted to the next hop router, and the packet bypass included in the setup response message repeatedly received in response to the setup request message is provided. A packet bypass manager configured to set and manage a packet bypass time based on a pass time;
A bypass buffer unit for storing a packet for bypass forwarding to the next hop of the packet routing path; And
And a packet forwarding unit configured to switch a packet received at the packet bypass time to the bypass buffer unit to control bypass forwarding to the next hop router through the bypass buffer unit without packet processing. 2. The method of claim 1,
Router using an integrated service model for transmitting and receiving packets using the resource reservation protocol. 3. The method of claim 2,
Router characterized in that the packet is a real-time streaming packet The method of claim 3, wherein the standard time setting unit
And the standard time is synchronized by a PTP (Precision Time Protocol) method of the IEEE 1588 standard. The method of claim 3, wherein the packet forwarding unit
A bypass time determining unit that determines whether the packet reception time is received at the packet bypass time based on the packet reception time; And
And a size determination unit determining the size of the received packet and determining whether the packet is a bypass packet based on the size of the received packet when the packet is received at the packet bypass time. The method of claim 3, wherein the packet bypass management unit
A setup request message generation unit for repeatedly generating a setup request message including packet reception delay time information with a previous hop router in the packet routing path and transmitting the same to a next hop router; And
And a bypass time setting unit configured to set a packet bypass time based on the packet bypass time included in the configuration response message repeatedly received in response to the configuration request message. The method according to claim 6,
And the setup request message and the setup response message are transmitted and received a predetermined number of times. The method of claim 7, wherein the setting request message generating unit
A delay time calculator configured to calculate a packet reception delay time from a packet reception time of a previous hop router and a standard time of the router in the packet routing path; And
And a message generator for generating a setting request message including the calculated packet reception delay time information.

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