CN100452764C - Mobile router device, mobile network system, and mobile management method of mobile router device - Google Patents

Abstract

A mobile router device connects a mobile network containing several terminal devices and moving in a backbone network with the backbone network. The mobile router device includes: means for deciding whether to operate as a master router which is a router for actually connecting the mobile network with the backbone network; means for recording a virtual address as an address common to the mobile router devices belonging to the mobile network and generating for this virtual address, a care-of address which is an address that the mobile router can use at the moving destination; and means for generating and transmitting a binding update message for correlating the virtual address to the care-of address when the mobile router device operates as the master router.

Description

Mobile router device, mobile network system

technical field

The invention relates to a mobile router device that accommodates one or more terminal devices, moves in a backbone network, and is connected to the backbone network and terminal devices, and a mobile network system including the mobile router device and the terminal device.

Background technique

One of the communication methods of terminal devices that move in the Internet system, for example, "Detailed Illustration of IPv6 Ekispatto Guide" written by Hiroshi Ezaki, Yuji Sekiya, Hideaki Yoshito, and Tomohiro Ishihara, published by Show and System, May 25, 2002 Mobile IPv6 (MobileInternet Protocol Version 6) described in Japanese p.96-99. According to this protocol, even when a terminal device moves between different networks, it is possible to communicate using the same address.

In Mobile IPv6, when the terminal device is far away from the home link (home link) connected to the place where it should be originally located, the router advertisement message (advertise message) sent from the access router of the link currently connected ) obtains prefix information of the link currently connected, and generates a care of address (care of address) that can be temporarily used in the link from the home address (home address) that is the original address and the above prefix information.

Then, by sending a binding update (binding updata) message to the home agent (home agent), the care-of address is used as the primary care of address (primary care of address), and the home agent is registered on the home link of the terminal device. After receiving the binding update message from the terminal device, the home agent generates or updates a binding cache (binding cache) that specifies the association between the home address and the care-of address.

The home agent refers to the binding cache, and the agent receives packets addressed to the home address on the terminal device's home link. The home agent encapsulates the data packet received by the agent, and transfers it to the care-of address of the terminal device. The terminal device decapsulates the transmitted packet through the home agent, and receives the packet addressed to the home address of the terminal device.

Mobile IPv6 is a mobile network that assumes that terminal devices move, not that a certain network as a whole is assumed to move between different networks. Therefore, in this case, terminal devices must perform the above-mentioned processing.

In addition, JP-A-9-172451 discloses the following as a communication method for a terminal device accommodated in a mobile network. In addition to the IP (Internet Protocol) address that changes with movement, that is, the address equivalent to the care-of address, the router is also given a VIP (Virtual IP) address that does not change even if it moves in a different network, that is, the home address. The home agent refers to the address management table (AMT: Address Mapping Table) for clarifying the association between the VIP address and the IP address, and transfers the packet to the IP address. Hereinafter, it is referred to as the VIP method.

In the VIP method, a specific mobile router device accommodates a terminal device, and a packet addressed to the terminal device transmits the packet to the IP address of the specific mobile router through the home agent that manages the AMT, enabling communication. Compared with Mobile IPv6, the processing when moving does not need to be performed on the terminal device in the mobile network.

However, in the above-mentioned VIP method, when a specific mobile router device accommodating a terminal device in the mobile network is changed, processing accompanying movement is required in each terminal device.

That is, a plurality of mobile router devices on the mobile network serving as connection points between access routers on the Internet and the mobile network are installed. When the mobile router device is moved, the connection relationship between the specific mobile router device and the terminal device is disconnected, and the terminal device is moved from the currently used mobile router to the subordinate of another mobile router. Therefore, each terminal device must perform processing for clarifying the association between the home address and the care-of address for the home agent. As a result, the load on the network increases, and since all the terminal devices cannot simultaneously perform the physical address registration process, the completion time of the physical address registration process may vary greatly depending on the terminal device.

Contents of the invention

The present invention provides a mobile network system, a mobile router device, and a mobile management method for the mobile router device: in a mobile network used for moving between multiple access networks connected to the backbone network, multiple access networks are set in the mobile network. In the case of a mobile router device connected to a mobile network and an access network, the mobile router device used can be changed without increasing the load on the network.

To this end, the mobile router device of the present invention accommodates one or more terminal devices, and connects the mobile network at the first location and the backbone network with multiple access routers through the first access router among the multiple access routers , the mobile network moves within the backbone network by moving to a second location and connecting to a second access router of the plurality of access routers, having: determining whether the mobile router device for actually connecting the mobile network and the backbone network acts as a master A unit acting as a router; recording a virtual address common to mobile router devices belonging to the mobile networks located in the first and second positions, and generating a care-of address usable by the mobile router unit in the second position for the virtual address; and When the mobile router device acts as a master router, it generates and sends a binding update message corresponding to the virtual address and the care-of address; when it acts as a master router, it has a structure for sending a binding update message; Wherein, the mobile network further includes a backup router device, and if the backup router device determines that the connection with the backbone network is lost between the mobile router device and the first access router, the backup router device sends another binding update message, and the other binding The predetermined update message includes a virtual address corresponding to the mobile router device and a care-of address corresponding to the standby router device.

According to this configuration, even when the router device used in the mobile network is changed, it is not necessary to send the location information of the mobile router device used in advance to manage the mobile router device in the home agent. The binding update message attribution of the old message. Only the mobile router device actually connected to the Internet performs binding update processing to the home network using the same virtual address, so the communication between the terminal device in the mobile network and the terminal device as a communication target can be continued.

In addition, in the home agent in the home network, the home address corresponding to the care-of address indicating the destination of the mobile router device is unique regardless of the change of the mobile router device, so there is no need to change the setting of the delivery route.

Furthermore, the mobile router device according to the present invention has a configuration in which the virtual address is a real address assigned to any one of the mobile router devices belonging to the mobile network. According to this configuration, since it is not necessary to assign new common addresses, it is possible to save address space. Also, even a mobile router device that has not been assigned an address in advance can operate as a mobile router device based on the virtual address.

In addition, the mobile router device according to the present invention has: a unit for monitoring the quality of the link connected to the backbone network; a unit for changing the priority of the main router and the backup router according to the link quality; Whether or not the mobile router device operates as a unit of the main router. According to this configuration, since the mobile router device with the best connection quality to the backbone network can be operated as the master router, high-quality communication can be performed even when moving.

In addition, the mobile router device according to the present invention may store the sequence number of the binding update message in the master router advertisement packet notifying the mobile router device that it is the master router when the mobile router device operates as the master router. And send the unit of the master router advertisement packet.

According to this structure, a plurality of mobile router devices are installed in the mobile network, and even if the mobile router device that performs binding update processing is changed in the home agent, it can continue to receive the latest sequence number and perform binding update processing, so it is possible to ensure that the message contains The latest information, and can prevent the home agent from judging the above information as old information and discarding it.

In addition, the mobile router device according to the present invention has means for receiving a master router advertisement packet sent by another mobile router device when the mobile router device is operating as a backup router, and the master router advertisement packet transmits the Notifying the mobile router device that another mobile router device works as a master router; recording the sequence number of the binding update message contained in the received master router advertisement packet to be used when the mobile router device itself becomes the master router The unit of the sequence number mentioned above. According to this structure, a plurality of mobile router devices are installed in the mobile network, and even if the mobile router device that performs the binding update process in the home agent is changed, it can continue to receive the latest sequence number and perform the binding update process, so that the message can be guaranteed. It contains the latest information and can prevent the home agent from judging the above information as old information and discarding it.

Furthermore, the mobile router device according to the present invention has a structure in which the master router advertisement packet uses the virtual router advertisement according to the virtual router redundancy protocol. According to this configuration, since each mobile router device using the virtual redundancy protocol notifies the other router device of the latest sequence number, it is possible to prevent the mobile router device from sending a new message. Therefore, an increase in the number of messages sent into the mobile network can be prevented.

In addition, the mobile router device according to the present invention has a structure in which the master router advertisement packet uses an IPv6 router advertisement message. According to this configuration, since the mobile router device operating as a router device notifies the latest sequence number to other router devices, it is possible to prevent the mobile router device from sending a new message. Therefore, it is possible to prevent an increase in the number of messages being sent into the mobile network.

Furthermore, the mobile network system according to the present invention includes: a plurality of mobile router devices; at least one terminal device accommodated in the mobile router device; and a home agent device that manages movement of the mobile router device. According to this structure, even if one mobile router device cannot be connected to the backbone network, and other router devices can be connected to the backbone network, it can be used instead without adding new processing and functions to the terminal or the home agent device. mobile router device to continue communication.

Furthermore, the mobile network system according to the present invention is configured such that at least one mobile router device has a backbone network physical interface type different from the backbone network physical interface types of other mobile router devices. According to this configuration, communication can be continued even when moving between various types of access networks.

In addition, the mobile network system according to the present invention has the following features: using the same virtual address on the backbone network side of each mobile router device, implementing a virtual redundant router protocol on the mobile network side, and using the mobile router device itself as the master router. The same virtual address to communicate with the structure. According to this configuration, the home address corresponding to the care-of address indicating the destination of the mobile router device is unique regardless of the change of the mobile router device. A communication terminal within the network is accompanied by a change of the mobile router device.

In addition, the mobile network system of the present invention has such a structure: the mobile router as the master router sends a binding update message for mobility management using the same virtual address and a care-of address generated corresponding to the same virtual address to Home agent device.

According to this configuration, even when the mobile router used in the mobile network is changed, it is not necessary to send the location information for the previously used mobile router device to manage the mobile router device in the home agent. The binding update message for the old information. Only the mobile router device actually connected to the Internet performs binding update processing to the home network using the same virtual address, so the communication between the terminal device in the mobile network and the terminal device as a communication target can be continued.

In addition, in the home agent in the home network, the home address corresponding to the care-of address indicating the destination of the mobile router device is unique regardless of the change of the mobile router device, so the setting change of the delivery route is not required.

In addition, the mobile router device according to the present invention is included in a mobile network system, and the mobile network system includes: one or more terminal devices; a mobile router device, the plurality of mobile router devices including a primary router device and a backup router device; and a home agent device that associates and manages a home address with a care-of address.

the mobile network moves from a home network connected to a first location within the backbone network to a second location within the backbone network, when the primary router at the first location is still acting as the primary router after the mobile network has moved to the second location, The mobile router device associates a care-of address corresponding to the virtual address generated after moving to the second location with the virtual address and registers the care-of address in the home agent device, and, if the standby router device determines that the care-of address is in the main When the connection between the router device and the backbone network is lost with the backbone network, the backup router device sends a binding update message, the binding update message includes the virtual address corresponding to the main router device and the virtual address corresponding to the backup router device. Another care-of address.

According to this configuration, when the mobile network moves, even if the mobile router device actually used to connect the backbone network to the mobile network is replaced, even if it is equivalent to the case where the currently used mobile router device moves, that is, there are multiple The router device can be managed by the home agent as one mobile router device, and there is no need to change the setting of the delivery route.

In addition, even when the mobile router device used in the mobile network is changed, it is not necessary for the previously used mobile router device to send a message for clearing old data in the binding cache for managing the location information of the mobile router device in the home agent. Informational binding update message. Only the mobile router device actually connected to the network performs the binding update process to the home network using the same virtual address, so that the communication between the terminal device in the mobile network and the terminal device serving as a communication target can be continued.

Furthermore, in the mobile router device according to the present invention, the virtual address is any one of the physical addresses used at the backbone network side physical interface when each mobile router device belonging to the mobile network is connected to the home network.

According to this configuration, since it is not necessary to assign new common addresses, it is possible to save address space. Also, even a mobile router device that has not been assigned an address in advance can operate as a mobile router device based on the virtual address.

In addition, in the mobile router device according to the present invention, in order to notify the home agent device that the mobile router device operates as a master router, the master router advertisement packet sent to the mobile network includes the above-mentioned virtual address and another message sent to the home agent device. A sequence number for a binding update message.

According to this structure, even if the mobile router device that performs the binding update process is changed in the home agent, the latest sequence number can be inherited and the binding update process can be performed, so it can be ensured that the message contains the latest information, and the home agent can prevent the above-mentioned The information is judged as old information and discarded.

Furthermore, in the mobile router device according to the present invention, the master router advertisement packet is a virtual router advertisement packet used by a virtual router redundancy protocol implemented on the mobile network side of the mobile router device. According to this configuration, since each mobile router device using the virtual redundancy protocol notifies the latest sequence number to other router devices, it is possible to prevent the mobile router device from sending a new message, and therefore it is possible to prevent the message from being sent to the mobile network. increase in number.

In addition, in the mobile router device according to the present invention, the master router advertisement packet is an IPv6 router advertisement message transmitted to the mobile network side by the mobile router device operating as the master router. According to this configuration, since the mobile router device operating as a router device notifies the latest sequence number to other router devices, it is possible to prevent the mobile router device from sending a new message. Therefore, an increase in the number of messages transmitted within the mobile network can be prevented.

Description of drawings

FIG. 1 is a schematic diagram of a network system structure related to Embodiment 1 of the present invention;

Fig. 2 is a schematic diagram of the structure when the mobile network moves from the home network in the network system related to Embodiment 1 of the present invention;

3 is a schematic diagram of a configuration when a mobile router device for connecting a mobile network to the Internet is changed in the network system according to Embodiment 1 of the present invention;

FIG. 4 is a block diagram showing the configuration of a mobile router device according to Embodiment 1 of the present invention;

FIG. 5 is a schematic diagram of the steps of binding update processing related to Embodiment 1 of the present invention;

FIG. 6 is a schematic diagram of the structure of a binding update message related to Embodiment 1 of the present invention;

FIG. 7A is a schematic diagram of the format of the attribution of the migration header in the binding update message related to Embodiment 1 of the present invention;

7B is a schematic diagram of the format of the mobility header (mobility header) in the binding update message related to Embodiment 1 of the present invention;

FIG. 7C is a schematic diagram of a binding update format in a binding update message related to Embodiment 1 of the present invention;

Fig. 7D is a schematic diagram of the format of the proxy care-of-address migration header in the binding update message related to Embodiment 1 of the present invention;

FIG. 8 is a schematic diagram of the structure of a binding update message related to Embodiment 1 of the present invention;

FIG. 9A is a schematic diagram of the format of the home address option in the binding update message related to Embodiment 1 of the present invention;

FIG. 9B is a schematic diagram of the header format of the migration header in the binding update message related to Embodiment 1 of the present invention;

FIG. 9C is an illustration of the binding update format in the binding update message related to Embodiment 1 of the present invention.

FIG. 9D is a schematic diagram of the format of the proxy care-of-address migration option in the binding update message related to Embodiment 1 of the present invention;

FIG. 10 is a block diagram showing the configuration of a mobile router device according to Embodiment 1 of the present invention;

FIG. 11 is a sequence diagram showing an example of a mobility management method according to Embodiment 1 of the present invention;

Fig. 12 is a schematic diagram of the structure of the router advertisement message related to Embodiments 1 and 2 of the present invention;

FIG. 13A is a schematic diagram of the router advertisement message format related to Embodiments 1 and 2 of the present invention;

FIG. 13B is a schematic diagram of the format of the prefix information option in the router advertisement message related to Embodiments 1 and 2 of the present invention;

Fig. 13C is a schematic diagram of the advertisement interval option format in the router advertisement message related to Embodiments 1 and 2 of the present invention;

FIG. 13D is a schematic diagram of the format of the sequence number option format of the binding update message in the router advertisement message related to Embodiments 1 and 2 of the present invention;

FIG. 14 is an example diagram of a binding cache related to Embodiment 1 of the present invention;

FIG. 15 is a sequence diagram showing an example of a mobility management method according to Embodiment 1 of the present invention;

FIG. 16 is an example diagram of a binding cache related to Embodiment 1 of the present invention;

FIG. 17 is a schematic diagram of the structure of a network system related to Embodiment 2 of the present invention;

FIG. 18 is a schematic diagram of the structure when the mobile network moves from the home network in the network system related to Embodiment 2 of the present invention;

19 is a schematic diagram of a configuration when a mobile router device for connecting a mobile network to the Internet is changed in the network system according to Embodiment 2 of the present invention;

FIG. 20 is a block diagram showing the configuration of a mobile router device according to Embodiment 2 of the present invention;

FIG. 21 is a schematic diagram of the steps of binding update processing related to Embodiment 2 of the present invention;

FIG. 22 is a schematic diagram of the structure of a binding update message related to Embodiment 2 of the present invention;

Fig. 23A is a schematic diagram of the format of the home address option in the binding update message related to Embodiment 2 of the present invention;

FIG. 23B is a schematic diagram of the header format of the migration header in the binding update message related to Embodiment 2 of the present invention;

FIG. 23C is a schematic diagram of a binding update format in a binding update message related to Embodiment 2 of the present invention;

Fig. 23D is a schematic diagram of the format of the proxy care-of address migration option in the binding update message related to Embodiment 2 of the present invention;

FIG. 24 is a block diagram showing the configuration of a mobile router device according to Embodiment 2 of the present invention;

FIG. 25 is a sequence diagram showing an example of a mobility management method according to Embodiment 2 of the present invention;

FIG. 26 is an example diagram of a binding cache related to Embodiment 2 of the present invention;

FIG. 27 is a sequence diagram showing an example of a mobility management method according to Embodiment 2 of the present invention;

FIG. 28 is an example diagram of a binding cache related to Embodiment 2 of the present invention;

FIG. 29 is a sequence diagram of a virtual redundant router protocol related to Embodiment 2 of the present invention;

FIG. 30 is a schematic diagram of the VRRP field format related to Embodiment 2 of the present invention.

Detailed ways

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram of a network system structure related to Embodiment 1 of the present invention.

In FIG. 1 , a mobile network 1 connected to a home network 20 is shown connected to the Internet (backbone network) 8 via a gateway 7 . The mobile network 1 has mobile router devices MR2, MR3 (also written as mobile routers 2, 3) and a terminal device LFN5. The interfaces on the backbone network 8 side in the mobile router devices MR2 and MR3 have the same or different physical interfaces.

Examples of the interface on the backbone network 8 side include Ethernet (registered trademark) method, IEEE802.11 (a, b, e, g, etc.) method, HIPERLAN method, IMT-2000 method, PDC method, GPRS method, and HPS method. way etc. In addition, the interface on the mobile network 1 side uses the same interface, for example, Ethernet method, Bluetooth method, UWB (Ultra Wide Band) method, IEEE802.11 (a, b, e, g, etc.) method.

In the example of FIG. 1, the mobile network 1 is connected to the home network 20 via the mobile router device MR2, and the mobile router device MR3 is only connected to the interface on the mobile network side and not connected to the interface on the backbone network side. In addition, the address of the backbone network side interface of the mobile router device MR2 is MR2-HoA, the address of the mobile network side interface is MR3-In, and the address of the mobile network side interface of the mobile router device MR3 is MR3-HoA

Also, mobile router device MR2 connecting home network 20 and mobile network 1 transmits router advertisement message 1010 as shown in FIG. 13A to mobile network 1 . In addition, in the option field 1020 of the router advertisement message 1010, as shown in FIG. 12, the prefix information option 1030 shown in FIG. 13B is included. The default router of the terminal LFN5 is therefore MR2-In, and furthermore the next hop to the mobile network 1 of the home gateway HGW7 is MR2-HoA.

When the communication partner terminal device CN11 transmits a packet addressed to the terminal device LFN5, the transmitted packet reaches the home gateway HGW7 based on the routing information in the Internet 8 . In home gateway HGW7, data packets destined for mobile network 1 are sent to MR2-HoA. The mobile router device MR2 transmits the packet addressed to the terminal device LFN5 to the mobile network 1, and sends the packet to the terminal device LFN5.

On the other hand, packet transmission from the terminal device LFN5 to the communication partner terminal device CN11 is performed as follows. The terminal device LFN5 transmits a packet addressed to the communication partner terminal device CN11 to the mobile router device MR2 which is the default router MR2-In. When the mobile router device MR2 receives a data packet sent to the communication partner terminal device CN11, it determines whether the destination of the data packet is a terminal belonging to the home network 20. The home gateway HGW7 of a hop transmits. Home gateway HGW7 transmits the received packet to the Internet 8 because the destination of the received packet is not the packet to its own home network 20 , and sends it to the communication partner terminal device CN11 via the Internet 8 .

Next, the movement management method when the connection point to the Internet 8 is changed due to the movement of the mobile network 1 will be described with examples shown in FIGS. 2 and 11 .

As shown in FIG. 2 , it is assumed that the mobile network 1 leaves the home network 20 and moves under the control of the access router AR9 having the same physical connection as the backbone network side interface of the mobile router device MR2 ( S901 ). At this time, the mobile router device MR2 receives the router advertisement message transmitted from the access router AR9 (S902). The care-of address MR2-CoA temporarily used by the access router AR9 is generated from the prefix information contained in the router advertisement message (S903).

In addition, FIGS. 13A to 10D are example diagrams of the format of the router advertisement message 1010. The option field 1020 of the router advertisement message 1010 in FIG. 13A contains the prefix information option 1030 in FIG. 13B and the advertisement interval option 1050 in FIG. 13C.

Next, the mobile router device MR2 generates a binding update message 600 (S904) storing the home address MR2-HoA603 and the care-of address MR2-CoA634 as illustrated in Figure 6 and Figures 7A to 7D (S904), and sends the ( S905). As a result, the care-of address MR2-HoA is registered in the home agent HA6 on the home network 20 of the mobile network 1 as the primary care-of address.

After receiving the binding update message 600, the home agent HA6 generates a binding cache 1100 specifying the association between the home address MR2-HoA and the care-of address MR2-CoA (S906). The mobile network 1 completes the transfer preparation to the mobile network 1 after moving from the home network 20 (S907). Fig. 14 is an example diagram of the binding cache 1100, which specifies and stores the association between the home address 1101, the care-of address 1102, the valid time 1103, the flag 1104, the sequence number 1105 and the customary information 1106.

Furthermore, the mobile router device MR2 generates a router advertisement message including not only the prefix information option 1030 in the option field 1020 of the router advertisement message 1010, but also the binding message sequence number option 1070 as shown in FIG. 1 send. The sequence number is stored by the mobile router device subordinate to the mobile network 1 that received the router advertisement message 1010 containing the binding update message sequence number option 1070.

The packet addressed to the terminal device LFN5 transmitted from the communication partner terminal device CN11 reaches the home gateway HGW7 based on the routing information in the Internet 8 . In the home gateway GHW7, the data packet destined for the mobile network 1 is transmitted to the MR2-HoA.

However, in the home agent HA6, since it has the binding cache 1100 of MR2-HoA and the care-of address MR2-CoA, the home agent HA6 captures the above-mentioned data packet, encapsulates the data packet addressed to the terminal device FLN5, and sends the data packet to the mobile router device MR2 The MR2-CoA of the care-of address is sent. The encapsulated packet is delivered to the mobile router device MR2 via the access router AR9, decapsulated in the mobile router device MR2, and transmitted to the terminal device LFN5.

On the other hand, packet transmission from the terminal device LFN5 to the communication partner terminal device CN11 is performed as follows. The terminal device LFN5 transmits a packet addressed to the communication partner device CN11 to MR2-In which is the default router, that is, the mobile router device MR2. When receiving the packet addressed to the communication partner terminal device CN11, the mobile router device MR2 encapsulates the packet addressed to the communication partner terminal device CN11 and transfers it to the home agent HA6.

The encapsulated data packet is sent to the home agent HA6 via the access router AR9, uncapsulates in the home agent HA6, and checks the result sent to the destination address. send.

Next, a mobility management method when an access link usable by the mobile router device MR2 cannot be found but an access link usable by the mobile router device MR3 is found, will be described with reference to FIGS. 3 and 15 . .

As shown in FIG. 3 , it is assumed that the mobile network 1 leaves the home network 20 or the visited network 21 and moves to the subordinate of the access router AR10 having the same physical link as the backbone network physical interface of the mobile router device MR3 ( S1201 ).

At this time, even if the mobile router device MR2 receives the last router advertisement message 1010 sent by the access router AR9, even if a time greatly exceeding the router advertisement interval 1054 included in the router advertisement message 1010 has elapsed (e.g. , Advertisement Interval×3), when the next Router Advertisement message 1010 cannot be received yet, it is determined that the connectivity with the access router AR9 is lost.

Also, the mobile router device MR3 receives the router advertisement message 1010 from the access router AR9 (S1202). The mobile router device MR3 acquires the prefix information 1043 from the router advertisement message 1010, and generates a care-of address MR3-CoA temporarily used under the control of the access router AR10 (S1203).

Next, the mobile router device MR3 detects that the transmission of the router advertisement message 1010 periodically transmitted from the mobile router device MR2 is stopped. Even if the time (for example, advertisement interval×3) greatly exceeding the router advertisement interval 1054 included in the router advertisement message 1010 has elapsed since the latest router advertisement message 1010 transmitted by the mobile router device MR2 is received, When the next router advertisement message 1010 cannot be received, it is determined that the transmission of the router advertisement message 1010 periodically transmitted from the mobile router device MR2 has been stopped.

At this time, as shown in FIG. 8 and FIG. 9 , instead of the home address of the own mobile router MR3, the home address of the mobile router MR2 operating as a connecting router when the mobile network 1 is connected to the home network 20 MR2-HoA, as Home Address 603 in the Binding Update message, stores the Care-of-Address MR3-CoA 734.

Furthermore, the binding update message 700 is generated that stores the sequence number of the sequence number 621 that is notified from the mobile router device MR2 through the binding update message sequence number option 1070 of the router advertisement message 1010 by adding 1 (S1204). By sending the generated binding update message 700 to the home agent HA6 (S1205), the care-of address MR3-HoA is used as the primary care-of address to register in the home agent HA6 on the home network 20 of the mobile network 1 .

After receiving the binding update message 700, the home agent HA6 generates a binding cache 1300 specifying the association between the home address MR2-HoA and the care-of address MR3-CoA (S1206). The mobile network 1 completes the transfer preparation to the mobile network 1 after moving from the home network 20 (S1207).

Fig. 16 is an example diagram of a binding cache 1300, which clarifies and stores the association between the home address 1101, the care-of address 1302, the valid period 1103, the flag 1104, the sequence number 1105 and the customary information 1106.

Mobile router MR2 that lost connection to the external network stops sending Router Advertisement message 1010 to mobile network 1, and mobile router MR3 that reconnects to the external network starts sending Router Advertisement message 1010 to the mobile network. Thus, after the valid time 1040 included in the last router advertisement message transmitted from the mobile router device MR2, the default router of the terminal device LFN5 becomes MR3-In.

A packet addressed to the terminal device LFN5 transmitted from the communication partner terminal device CN11 reaches the home gateway HGW7 based on the routing information in the Internet 8 . In home gateway HGW7, data packets destined for mobile network 1 are delivered to MR2-HoA.

However, in the home agent HA6, since it has the binding cache 1300 of MR2-HoA and the care-of address MR2-CoA, the home agent HA6 captures the above-mentioned data packet, encapsulates the data packet sent to the terminal device FLN5, and sends it to the mobile router device MR3-CoA delivery of MR3's care-of-address.

The encapsulated packet is sent to the mobile router device MR3 via the access router AR10, decapsulated by the mobile router device MR3, and transmitted to the terminal device LFN5.

On the other hand, packet transmission from the terminal device LFN5 to the communication partner terminal device CN11 is performed as follows. The terminal device LFN5 transmits a packet addressed to the communication target device CN11 to the mobile router device MR3 of the MR3-In which is the default router. When the mobile router device MR3 receives the packet addressed to the communication partner terminal device CN11, it encapsulates the packet addressed to the communication partner terminal device CN11 and transfers it to the home agent HA6.

The encapsulated data packet is sent to the home agent HA6 via the access router AR10, decapsulated in the home agent HA6, and the result after checking the destination address, because the destination does not belong to the home network 20, it is sent to the communication object terminal via the Internet 8. Device CN11 transmits.

Next, an example of the configuration of the mobile router devices MR2 and MR3 is shown in FIG. 4 and described.

4 is a schematic diagram of a configuration example of mobile router devices MR2 and MR3, which are composed of a backbone network physical interface 12, an L3 processing unit 13, a mobile network physical interface 14, a MobileIPv6 processing unit 15, and a mobility management processing unit 23.

The backbone network physical interface 12 performs the following processing: the physical layer processing and the data link layer processing of the data packet received from the backbone network 8 side are processed and forwarded to the L3 processing unit 13; Data link layer processing and physical layer processing are performed on packets received from the L3 processing unit 13 .

The mobile network physical interface 14 performs the following processing: performing physical layer processing and data link layer processing of data packets received from the mobile network 1 side and forwarding them to the L3 processing unit 13; Data link layer processing and physical layer processing are performed on packets received from the L3 processing unit 13 .

The L3 processing unit 13 performs network layer processing on data packets that are accepted and handed over between the backbone physical interface 12 and the mobile network physical interface 14 .

Furthermore, in the L3 processing unit 13, the router advertisement message 1010 is generated, sent and received, and it is judged whether other router devices in the mobile network are mobile router devices for monitoring connectivity with the backbone network, and for The mobile router device that connects the mobile network and the backbone network operates.

In addition, in the L3 processing unit 13, the MobileIPv6 processing in the packet is handed over to the MobileIPv6 processing unit 15 as necessary.

The MobileIPv6 processing unit 15 processes the packet based on the MobileIPv6 processing procedure among the packets received from the L3 processing unit 13 , and transfers the packet to the L3 processing unit 13 . In addition, the home address and sequence number are received from the mobility management processing unit 23, and a packet for performing mobility management of the mobile network 1 is generated based on the home address, and handover processing to the L3 processing unit 13 is performed.

The mobility management processing unit 23 performs the following processing: the L3 processing unit receives and stores the prefix information contained in the admission advertisement message received at the physical interface of the backbone network for detecting movement; the prefix information stored in the mobile router device in the mobile network 1 Processing of the home address used in the backbone physical physical interface 12; processing of storing the sequence number used in the binding update message; processing to MobileIPv6 in order to use the home address for mobility management in the case of connecting to the visited network during movement The section 15 transfers the processing of the address and sequence number.

The basic operation of the mobile router device MR2 configured as shown in FIG. 4 will be described. The packet transfer operation of the mobile router device MR2 shown in FIG. 4 is as follows. In addition, the mobile router device MR3 also has the same configuration and performs the same operation.

The mobile router device MR2 monitors the state of the physical interface 12 of the backbone network. By the backbone network side, when receiving the router advertisement message containing the prefix information option 1030 and the advertisement interval option 1050, it is judged that the physical interface 12 of the backbone network is in the state of being connected to the network, and the connection state is determined by the received router advertisement message 1010 at last. , when the next router advertisement message 1010 having the same prefix information 1043 cannot be received even after a certain period of time, it is determined that the connectivity is lost.

Also, at the same time, it is determined whether there is a mobile router device operating as a mobile router connecting the mobile network to the backbone network within the mobile network. That is, when the router advertisement message 1010 is periodically sent from another router device on the mobile network side, it is determined that a mobile router device operating as a mobile router exists in the mobile network, and otherwise, it is determined that such a mobile router device does not exist.

When the backbone network physical interface 12 is connected to the network and there is no mobile router device operating as a mobile router that connects the mobile network to the backbone network, it operates as a router device and performs communication between the backbone network 8 and the mobile network 1. Packet transfer processing.

When the mobile router device MR2 operates as a router device, after performing physical layer protocol processing and data link protocol processing on the network physical interface 12, it transmits the data packet received from the backbone network 8 to the L3 processing unit 13 that performs IP protocol processing. While performing IP processing, the MobileIPv6 processing unit 15 performs additional IP header processing related to MobileIPv6 according to the MobileIPv6 processing procedure. Thereafter, the result of the routing processing in the L3 processing unit 13 is transmitted to either the backbone network physical interface 12 or the mobile network physical interface 14 .

On the other hand, for the data packet received from the mobile network 1, after being processed by the physical interface 14 of the mobile network, it is also transmitted to the L3 processing unit 13 that performs IP protocol processing. While implementing IP processing, the MobileIPv6 processing unit 15 follows The MobileIPv6 processing process performs additional IP header processing related to MobileIPv6. Thereafter, the result of the routing processing in the L3 processing unit 13 is transmitted to either the backbone network physical interface 12 or the mobile network physical interface 14 .

In addition, the L3 processing unit 13 generates a router advertisement message 1010 in which the prefix information option 1030 is stored in the option field 1020 , and transmits the generated message packet to the mobile network physical interface 14 .

Also, when the device itself is not operating as a router device, the transfer packet is discarded without performing processing on the transfer packet, and the generation of a router advertisement message is also not performed. Further, the mobile network physical interface receives, and the data packet transmitted by the L3 processing unit is the router advertisement message 1010 sent by other router devices, and when the binding update message sequence number option 1070 is not included, the sequence number is notified to the mobility management processing unit 23, The mobility management processing unit 23 that has received the notification of the sequence number stores the sequence number.

Next, the binding update processing operation of the mobile router device MR2 when the mobile network 1 moves from the home network 20 will be described with reference to FIGS. 5 to 7 .

FIG. 5 is a diagram showing a binding update processing procedure of the mobile router device MR2. The mobile router device MR2, through the mobility management processing unit 23, checks the prefix prefix 1043 of the prefix information option 1030 included in the router advertisement message 1010 received by the L3 processing unit 13 from the backbone network physical interface 13, and receives When the prefix contained in the router advertisement message of the router advertisement message is different, it is detected that the connection point to the backbone network 8 has changed (S51).

When movement is detected, a care-of address is generated from the prefix information 1043 and the virtual address included in the router advertisement message 1010 from the mobile network 8 (S52). When generating the care-of address, it is judged whether or not it operates as a router device (S55). When operating as a router device, a binding update message 600 as shown in FIG. 6 is generated and transmitted (S56).

In the binding update message 600, the extension header of the IPv6 destination address option header contains at least the home address option 605 and the migration header 610, and the message data in the migration header contains at least the binding update 620, and the migration in the binding update The option contains at least proxy care-of address option 630. In addition, in the sequence number field 621 in the binding update 620 , a sequence number obtained by adding 1 to the sequence number stored in the mobility management processing unit 23 is stored.

If no movement is detected, it is determined whether a binding response message for the previously sent binding update message is received (S53). Whether it is the effective elapsed time of the previously sent binding update message, the determination of the next message sending timing (S54), and when the itself is acting as a router device (S55), if necessary, generate and send a binding update message 600 (S56).

Furthermore, after sending the binding update message 600 , the mobility management processing unit 23 updates the saved sequence number to the sequence number already stored in the sequence number field 621 of the sent binding update message 600 .

Furthermore, in the mobile router device MR2 operating as a router device, when the mobility management processing unit 23 determines that it has moved, the mobility management processing unit 23 notifies the L3 processing unit 13 of the sequence number 621 of the binding update message 600 Stored sequence number. In the L3 processing unit 13, the router address message 1010 containing the binding message sequence number option 1070 and the prefix information option 1030 containing the notification sequence number stored in the binding message sequence number 1074 is generated, and sent to the mobile network physical interface 14. The mobile network physical interface 14 transmits to the mobile network 1 .

In addition, mobile router device MR2 may also have the function of generating and transmitting data packets and the function of receiving data packets as a terminal. The structure in this case is shown in FIG. 10 , and will be described below. The basic configuration is the same as that shown in FIG. 4 , but it also includes an upper layer processing unit 17 that performs higher layer processing such as TCP and UDP, and an application processing unit 18 that performs application control.

The basic operation of the mobile router device MR2 configured as above will be described below. The transmission operation initiated by the mobile router device MR2 configured as shown in FIG. 10 is performed as follows.

Data generated by the application processing unit 18 for transmission to the Internet 8 is transmitted to the L3 processing unit 13 for IP protocol processing via the upper layer processing unit 17 for processing in accordance with protocols such as socket, TCP, or UDP. Along with IP processing, the MobileIPv6 processing unit 15 that performs processing in accordance with the MobileIPv6 processing procedure performs additional IP header processing related to MobileIP. After the physical interface 12 of the backbone network performs data link protocol processing and physical layer protocol processing, it is sent to the backbone network 8 .

In addition, the transmission data generated by the application processing unit 18 of the mobile router device MR2 for transmission to the mobile network 1 is sent to the higher layer processing unit 17 that performs processing according to protocols such as socket, TCP, or UDP to the IP protocol processing unit 17. The L3 processing unit 13 transmits. Implement IP processing, and send to the mobile network 1 after data link protocol processing and physical layer protocol processing are performed on the mobile network physical interface 14.

In addition, the reception operation of the mobile router device MR2 as a terminal is performed as follows in the opposite operation to the transmission operation.

After the data packet received from the backbone network 8 is processed by the physical layer protocol and the data link protocol at the physical interface 12 of the backbone network, the L3 processing unit 13 performs IP protocol processing, and the MobileIPv6 processing unit 15 performs additional functions related to MobileIP at the same time. IP header processing. Next, the processing of the upper layer processing unit 17 is performed, and the data is sent to the application processing unit 18 .

After the data packet received from the mobile network 1 is processed by the physical layer protocol and the data link protocol at the mobile network physical interface 14 , it is processed by the IP protocol at the L3 processing unit 13 . Next, the processing of the upper layer processing unit 17 is performed, and the data is sent to the application processing unit 18 .

In addition, in this embodiment, two mobile router devices and one terminal device are described, but of course, it is also applicable to a case where a plurality of devices exist.

As described above, in this embodiment, in a mobile network having a plurality of mobile router devices, one of the addresses of the plurality of mobile router devices is assigned as a common address to the interface on the backbone network side of the mobile router device, and the use of By performing the binding update process based on the care-of address, it is possible to provide a terminal device in a mobile network that does not install MobileIPv6 to communicate while moving between various access networks without increasing the load on the network.

In addition, in this embodiment, the mobile router device operating as a router notifies the mobile router device not operating as a mobile router device existing in the same mobile network of the sequence number used for the binding update. When a mobile router device that is not operating as the router device is operated as a router device, the latest sequence number notified is updated. By performing binding update using the same virtual address as the mobile router device operating as a router device, there are a plurality of mobile router devices in the mobile network, and in the case of switching the mobile router device for connecting to the backbone network, The home agent can manage the latest mobile information without feeling the handover of the mobile router. Accordingly, even when a plurality of mobile routers are installed in a mobile network, it is possible to cope with movement without increasing the load on the network.

(Embodiment 2)

Fig. 17 is a diagram showing an example of the configuration of a mobile network system according to Embodiment 2 of the present invention.

FIG. 17 is an exemplary diagram in which the mobile network 1 connected to the home network 20 is connected to the Internet (backbone network) 8 via the home gateway 7 . The mobile network 1 has mobile router devices MR2 and MR3 and a terminal device LFN5. In the mobile router devices MR2 and MR3, the interfaces on the backbone network 8 side have the same or different physical interfaces.

Examples of the interface on the backbone network 8 side include Ethernet (registered trademark) method, IEEE802.11 (a, b, e, g, etc.) method, HIPERLAN method, IMT-2000 method, PDC method, GPRS method, and HPS method. wait. In addition, the interface on the mobile network 1 side uses the same interface, for example, Ethernet method, Bluetooth method, UWB (Ultra Wide Band) method, IEEE802.11 (a, b, e, g, etc.) method.

The mobile router devices MR2 and MR3 activate a virtual redundant router protocol, specifically VRRP (Virtual Router Redundancy Protocol), in the interface on the mobile network 1 side.

In the example shown in FIG. 17 , it is assumed that the priority for determining the relationship between the master router and backup router of the mobile router device MR2 is 100, and that the priority of the mobile router device MR3 is 80, and the physical interface on the backbone physical 8 side follows that on the mobile network 1 side. The relationship between the main router and the backup router of the physical interface, the router that becomes the main router is connected to the backbone physical and mobile networks. Here, the mobile router device MR2 operates as a master router, and the mobile router device MR3 operates as a backup router, which are indicated by solid lines and dotted lines in FIG. 17 .

On the physical interface on the mobile network 1 side, VRIP (MRi) is used as the virtual router IP address, and on the home network 20 side, VRIP (MRo) is used as the virtual router IP address. VRIP(MRi) and VRIP(MRo) follow the IPv6 address format, for example, VRIP(MRi) is 3ffe:0501::5F00:0202:2cff:fe00:000A, and VRIP(MRo) is 3ffe:0501::0100:0202:2cff :fe00:0001. The default gateway of the terminal LFN5 is therefore VRIP(MRi), the next mileage VRIP(MRo) of the mobile network 1 to the home gateway HGW7.

When the communication partner terminal device CN11 transmits a packet addressed to the terminal device LFN5, the transmitted packet reaches the home gateway HGW7 based on the routing information in the Internet 8 . In the home gateway HGW7, the data packet destined for the mobile network 1 is sent to the VRIP (MRo). The mobile router device MR2 serving as the main router transfers the packet addressed to the terminal device LFN5 to the mobile network 1, and sends the packet to the terminal device LFN5.

On the other hand, packet transmission from the terminal device LFN5 to the communication partner terminal device CN11 is performed as follows. The terminal device LFN5 transmits a packet addressed to the communication terminal device CN11 to VRIP (MRi) which is the default router. The mobile router device MR2 as the main router, when receiving the data packet sent to the communication object terminal device CN11, judges whether the destination address of the data packet is a terminal belonging to the home network 20, because the communication terminal device CN11 is not a terminal belonging to the home network 20 , so it is sent to the home gateway HGW7 as the next hop. Home gateway HGW7 transfers the received packet to the Internet 8 because the destination address of the received packet is not the packet to its own home network 20 , and reaches the communication partner terminal device CN11 via the Internet 8 .

When the mobile router device MR2 breaks down, or the mobile router device MR2 cannot receive the router advertisement message 1010 from the access router connected to the backbone network, the mobile router device MR2 cannot find the access link connected to the backbone network, and the data packet cannot be transmitted. When possible, the mobile router device MR3 serving as the backup router becomes the master router and transfers packets. At this time, since the interface address does not change to VRIP(MRo) or VRIP(MRi), the terminal device LFN5 does not need to perform any new processing in the home gateway HGW7.

Next, the mobility management method when the connection point to the Internet 8 is changed due to the movement of the mobile network 1 will be described with reference to FIGS. 18 and 25 .

As shown in FIG. 18 , it is assumed that the mobile network 1 leaves the home network 20 and moves under the control of the access router AR9 having the same physical link as the backbone network side interface of the mobile router device MR2 ( S2101 ).

At this time, the mobile router device MR2 receives the router advertisement message sent from the access router AR9 (S2102), and generates the care-of address CoA-9(MR) temporarily used under the access router AR9 from the prefix information contained in the router advertisement message. (S2103). As an example of a generation method, there is a method in which the upper bits (prefix length) of the address are the value of the obtained prefix, and the lower bits are the same bits as the corresponding bits of the virtual address.

In addition, FIG. 12 and FIG. 13A-FIG. 13D are exemplary diagrams of the format of the router advertisement message 1010. The router advertisement message 1010 contains the prefix information option 1030 shown in FIG. 12 and FIG. 13B, and the prefix information option 1030 shown in FIG. 12 and FIG. Ad Interval Options 1050. In addition, in this embodiment, it is not necessary to include the binding message sequence number option 1070 shown in FIG. 12 and FIG. 13D in the router advertisement message 1010 . Prefix length 1033 and prefix information 1043 are stored in prefix information option 1030 .

For example, when the prefix length 1033 in the prefix information option 1030 is 64 bits, and the prefix information 1043 is 3ffe:0501::1f00:3110:5aff:fe00:4326, the care-of address CoA-9 generated for the aforementioned VRIP (MRo) is 3ffe:0501::1f00:0202:2cff:fe00:0001.

In addition, as an example of the generation method, a method of making the lower bits of the generated address the same as the bits corresponding to the virtual address is shown, but the lower bits may be generated using other methods, for example, using random numbers.

Since the mobile router device MR2 works as a master router, it generates and stores the binding of the home address VRIP (MRo) 1903 and the care-of address CoA-9 (MR) 1934 as shown in FIGS. 22 and 23A to 23D. The update message 1900 (S2104) is sent to the home agent HA6 (S2105). Like this, the care-of address CoA-9 (MR) is used as the main care-of address, and the home agent HA6 on the home network 20 of the mobile network 1 logs in.

The home agent HA6, after receiving the binding update message 1900, generates a binding cache 2200 (S2106) that specifies the association between the home address VRIP (MRo) and the care-of address CoA-9 (MR), and sends the information to the mobile network 1 from the home network 20 The transfer preparation of the mobile network 1 after up-moving is completed (S2107). Fig. 26 is an example diagram of a binding cache 2200, which clarifies and stores the association between the home address 2201, the care-of address 2202, the validity period 2203, the flag 22104, the sequence number 2205 and the customary information 2206.

A packet addressed to the terminal device LFN5 transmitted from the communication partner terminal device CN11 reaches the home gateway HGW7 based on the routing information in the Internet 8 . In the home gateway GHW7, the data packet addressed to the mobile network 1 is transferred to the VRIP (MRo). However, in the home agent HA6, since the VRIP (MRo) and the binding cache 2200 of the care-of address CoA-9 (MR) are stored, the home agent HA6 captures the above-mentioned data packet, encapsulates the data packet sent to the terminal device FLN5 and Transfer to the care-of address CoA-9(MR) of the mobile router device MR2. The encapsulated packet is delivered to the mobile router device MR2 via the access router AR9, decapsulated in the mobile router device MR2, and transmitted to the terminal device LFN5.

Next, for the mobility management method when an access link usable by mobile router device MR3 is found when an access link usable by mobile router device MR2 cannot be found, the example diagrams shown in FIGS. 19 and 27 are used. to illustrate.

In the mobile router devices MR2 and MR3, the priority is changed according to the connectivity with the backbone network 8 . When it is possible to connect to the backbone network, the priority is set to the normal value, but when the receiving electric field strength becomes weak, making it impossible to receive regular router advertisement messages, etc., as the connectivity deteriorates, the value corresponding to the network bandwidth decreases, and in When no connectivity is obtained at all, the priority is 0. At this time, when the mobile router device MR3 can obtain connectivity, the mobile router device MR3 has a higher priority than the mobile router device MR2, and the mobile router device MR3 becomes the master router.

As shown in FIG. 19 , it is assumed that the mobile network 1 leaves the access network 21 and moves under the control of the access router AR10 having the same physical link as the backbone network physical interface of the mobile router device MR3 ( S2301 ). At this time, in the mobile router device MR2, the connectivity with the backbone network 8 deteriorates, and the router advertisement message 1010 from the access router AR9 cannot be received (S2310), and the router advertisement message 1010 from the access router AR10 is received by the mobile router device MR3. (S2302).

The mobile router device MR3 acquires the prefix information 1043 from the router advertisement message 1010, and generates a care-of address CoA-10(MR) temporarily used under the access router AR10 (S2303). For example, when the prefix length 1033 in the prefix information option 1030 contained in the router advertisement message 1010 received in S2302 is 64 bits, and the prefix information 1043 is 3ffe:0501::2f00:3110:5aff:fe00:4326, the above The care-of address CoA-10 generated by VRIP(MRo) is 3ffe:0501::2f00:0202:2cff:fe00:0001. In the mobile router devices MR2 and MR3, the priority is changed according to the connectivity with the backbone network as described above. When the value of this priority becomes higher, the mobile router MR3 becomes the master router (S2304).

Since the mobile router device MR3 works as a master router, thereafter, it generates a binding update message 1900 storing the home address VRIP(MRo) 1903 and the care-of address CoA-10(MR) 1934 as shown in FIG. 22 and FIG. 23A (S2305), and send to the home agent HA6 (S2306), so, the care-of address CoA-10 (MR) is used as the main care-of address, and the home agent HA6 on the home link of the mobile router device MR3 registers.

After the home agent HA6 receives the binding update message 1900 from the mobile router device MR3, it updates the binding cache of the home address VRIP (MRo) to clarify the association between the home agent VRIP (MRo) and the care-of address CoA-10 (MR) binding cache 2400 (S2307), and transfer preparation for replacing the mobile router device for connection to the backbone network 8 in the mobile network 1 is completed (S2308).

Hereinafter, when a packet is transmitted from the communication partner terminal device CN11 to the terminal device LFN5, the care-of address CoA-9 is obtained by replacing the case where the mobile network 1 is under the control of the access router AR9 with the case where the mobile network 1 is under the control of the access router AR10. (MR) is replaced by CoA-10(MR), and the same operation as above is performed, so the description is omitted.

Next, FIG. 20 shows an example of the configuration of the mobile router devices MR2 and MR3 and will be described.

20 is a schematic diagram of a configuration example of mobile router devices MR2 and MR3, which are composed of a backbone network physical interface 12, an L3 processing unit 13, a mobile network physical interface 14, a MobileIPv6 processing unit 15, a virtual router processing unit 16, and a mobility management processing unit 23. .

The backbone network physical interface 12 performs the following processing: the physical layer processing and the data link layer processing of the data packet received from the backbone network 8 side are processed and forwarded to the L3 processing unit 13; The L3 processing unit 13 performs data link layer processing and physical layer processing on packets received; monitors link quality indicating connectivity with the backbone network 8, and transfers connection information to the virtual router processing unit.

The mobile network physical interface 14 performs the following processing: perform physical layer processing and data link layer processing of the data packet received from the mobile network 1 side and transfer it to the L3 processing unit 13; The data link layer processing and physical layer processing are performed on the packet received by the L3 processing unit 13 .

The L3 processing unit 13 performs network layer processing on the data packets to be handed over between the backbone physical interface 12 and the mobile network physical interface 14 . Also, in the L3 processing unit 13, handover is performed to the MobileIPv6 processing unit 15 when MobileIPv6 processing is required in the packet, and handover to the virtual router processing unit 16 is performed when virtual router redundancy protocol processing is required. Furthermore, information indicating whether it is currently operating as a master router is received from the virtual router processing unit 16, and processing necessary for the case of being a master router is performed.

The MobileIPv6 processing unit 15 processes the packet received from the L3 processing unit 13 based on the MobileIPv6 processing procedure, and transfers the packet to the L3 processing unit 13 . In addition, the home address and sequence number are received from the mobility management processing unit 23, and a packet for performing mobility management of the mobile network 1 is generated based on the home address, and handover processing to the L3 processing unit 13 is performed.

The virtual router processing unit 16 performs processing for operating another mobile router in the same mobile network as one virtual router in accordance with the virtual redundant router protocol. The following processing is performed: processing of changing the priority based on the connectivity information from the backbone network physical interface 12, receiving processing of the virtual router advertisement packet obtained from the L3 processing unit 13, generating a virtual router advertisement packet and transferring it to the L3 processing unit 13 processing, and the processing of storing the information of whether it is the main router or the backup router in the mobility management processing unit 23. Furthermore, a process of transferring the sequence number included in the received virtual router advertisement to the mobility management processing unit 23 is also performed.

The mobility management processing part 23 performs the following processing: the processing of storing the address used in the backbone physical physical interface 12 of the mobile router device in the mobile network 1; the processing of saving the sequence number received by the virtual router processing part; The processing unit 16 receives information on whether it is a master router, and if it is a master router, transfers the address and sequence number to the MobileIPv6 processing unit 15 in order to perform mobility management using a virtual address.

The basic operation of the mobile router device MR2 configured as in FIG. 20 will be described. The packet transfer operation of the mobile router device MR2 shown in FIG. 20 is performed as follows. In addition, the mobile router device MR3 also has the same configuration and performs the same operation.

The mobile router device MR2 monitors its own status managed by the virtual router processing unit 16, and recognizes whether it is a master router or not.

When itself is the main router, the physical interface 12 of the backbone network performs physical layer protocol processing and data link protocol processing, and then transmits the data packet received from the backbone network 8 to the L3 processing unit 13 that performs IP protocol processing, and implements IP processing. , the MobileIPv6 processing unit 15 performs additional IP header processing related to MobileIPv6 according to the MobileIPv6 processing procedure. Thereafter, the result of the routing processing in the L3 processing unit 13 is transmitted to either the backbone network physical interface 12 or the mobile network physical interface 14 .

On the other hand, for the data packet received from the mobile network 1, after being processed by the physical interface 14 of the mobile network, it is transmitted to the L3 processing unit 13 which performs IP protocol processing. While implementing IP processing, the MobileIPv6 processing unit 15 follows the MobileIPv6 In the processing process, additional IP header processing related to MobileIPv6 is performed. Thereafter, the result of the routing processing in the L3 processing unit 13 is transmitted to either the backbone network physical interface 12 or the mobile network physical interface 14 .

Also, when it is a backup router itself, it does not perform processing related to the transfer packet and discards the transfer packet.

Next, the binding update processing operation of the mobile router device MR2 when the mobile network 1 moves from the home network 20 will be described with reference to FIGS. 21 to 23 .

FIG. 21 is a diagram showing the binding update processing procedure of the mobile router device MR2. When mobile router device MR2 detects movement (S51), it generates a care-of address from prefix information 1043 and virtual address included in router advertisement message 1010 from mobile network 8 (S52). When generating a care-of address, it is judged whether or not it operates as a master router device (S181). When operating as a master router device, it generates and transmits a binding update message 1900 as shown in FIG. 22 (S182).

As shown in Figure 22 and Figures 23A to 23D, in the binding update message 1900, the extension header of the IPv6 destination address option header contains at least the home address option 1905, the migration header 1910, and the message data in the migration header contains at least The binding update 1920 includes at least a proxy care-of address option 1930 in the migration option within the binding update. In the home address option 1905, a virtual address is stored in the home address field 1903 instead of the home address of the mobile router device itself. In addition, the V flag 1922 indicating that the virtual address is used in the binding update 1920 is reset.

In the case of not detecting movement, it is determined whether a binding response message (S53) for the previously sent binding update message is received, and whether it is the effective elapsed time of the previously sent binding update message, and the next message sending timing If it is determined (S54), when it operates as a master router (S181), if necessary, it generates and transmits a binding update message 600 (S182).

Furthermore, after sending the binding update message 600 , the mobility management processing unit 23 updates the stored sequence number to the sequence number stored in the sequence number field 621 of the sent binding update message 600 .

In addition, here, the so-called movement detection in S51 actually includes the case where the connection point with the Internet 8 is changed after the mobile network 1 moves, and also includes moving the router according to the virtual redundant router protocol activated on the mobile network 20 side. A case where the operating state of the device MR2 is physically changed from the backup router to the master router.

Next, for the mobile router device MR2, FIG. 29 shows an example of the procedure based on the virtual redundant router protocol, and the procedure for migrating from the mobile router device MR3 to the master router when the link environment deteriorates will be described below. Assume that mobile router device MR2 operates as a master router and mobile router device MR3 operates as a backup router.

The mobile router device MR2 serving as the master router periodically transmits a virtual router advertisement packet including the VRRP field 2600 shown in FIG. 30 from the mobile network physical interface (S2501). The virtual router advertisement packet contains priority information and advertisement interval of the mobile router device. When the mobile router device operating as a standby router has lower priority information in the packet than its own priority, or does not receive a virtual router advertisement packet from the main router within a certain timeout value determined from the advertisement packet In this case, the master router is no longer suitable and becomes the master router itself.

When the quality of the communication link between the mobile router MR2 and the access router AR9 deteriorates with the movement of the mobile network 1, the virtual router processing unit 16 in the mobile router device MR2 lowers the priority (S2502).

The mobile router device MR2 stores the priority information lowered according to the deterioration of the link environment, and continues to periodically transmit the virtual router advertisement packet (S2503).

When the mobile router device MR3 receives the virtual router advertisement packet, it refers to the priority information in the virtual router advertisement packet to verify whether its priority is lower than its own, and if its own priority is higher, it becomes the master router (S2504).

The mobile router device MR3 serving as the master router periodically transmits a virtual router advertisement packet storing its own priority from the mobile network physical interface 14 (S2505).

When the mobile router device MR2 receives a virtual router advertisement packet with a higher priority than its own (S2505), it becomes a backup router itself (S2506), stops sending virtual router advertisement packets, and stops processing as a router.

In the VRRP field of the virtual router advertisement packet in this embodiment, as shown in Figure 30, for the existing VRRP field, the M flag 1605 is reset. When this bit is set, the virtual redundant router acts as a mobile router, indicating that the virtual router The VRRP field 2600 of the advertisement packet includes a sequence number field 2613 . In the sequence number field 2613 in the VRRP field 2600, the value stored in the sequence number field 1921 in the previous binding update message 1900 is stored. When the master router has exchanged, 1 is added to the value of the sequence number field 2613 and included in the binding update message 1900 .

In addition, the mobile router device MR2 may also have the function of generating and transmitting data packets of the mobile router device MR2 itself and the function of receiving data packets as a terminal device. The configuration at this time is shown in FIG. 24 , and will be described below. The basic configuration is the same as that shown in FIG. 20 , but further includes a higher layer processing unit 17 that performs higher layer processing such as TCP and UDP, and an application processing unit 18 that performs application control.

The basic operation of the mobile router device MR2 configured as above will be described below. The transmission operation initiated by the mobile router device MR2 configured as shown in FIG. 24 is performed as follows.

The transmission data generated by the application processing unit 18 for transmission to the Internet 8 is transmitted to the L3 processing unit 13 for IP protocol processing via the upper layer processing unit 17 for processing in compliance with protocols such as sockets, TCP, or UDP, and then transmitted to the L3 processing unit 13 for IP protocol processing. At the same time of IP processing, the NobileIPv6 processing section 15, which performs the processing according to the MobileIPv6 processing procedure, performs additional IP header processing related to MobileIPv6, and after the backbone network physical interface 12 performs data link protocol processing and physical layer protocol processing, it sends to the backbone Network 8 sends.

In addition, at this time, since the source address is the original home address of the mobile router device or the care-of address for the original home address of the mobile router device, the binding for the care-of address has nothing to do with the master-backup in the virtual redundant router protocol. The fixed update process is carried out with the usual MobileIPv6.

In addition, the transmission data generated by the application processing unit 18 of the mobile router device MR2 for transmission to the mobile network 1 is sent to the higher layer processing unit 17 that performs processing according to protocols such as socket, TCP, or UDP to the IP protocol processing unit 17. The L3 processing unit 13 transmits, implements IP processing, and transmits to the mobile network 1 after performing data link protocol processing and physical layer protocol processing on the mobile network physical interface 14 .

In addition, the receiving operation of the mobile router device MR2 as a terminal device is an operation opposite to that of the transmitting operation, and is performed as follows.

After the data packet received from the backbone network 8 is processed by the physical layer protocol and the data link protocol on the physical interface 12 of the backbone network, the L3 processing unit 13 performs the IP protocol processing, and the MobileIPv6 processing unit 15 performs additional functions related to MobileIP at the same time. IP header processing. Next, the processing of the upper layer processing unit 17 is performed and the data is transferred to the application processing unit 18 .

After the data packet received from the mobile network 1 is processed by the physical layer protocol and the data link protocol at the mobile network physical interface 14, the L3 processing unit 13 performs IP protocol processing, and then performs the processing of the upper layer processing unit 17 and sends it to the application The processing unit 18 transfers data.

In addition, in this embodiment, two mobile router devices and one terminal device are described, but of course, it is applicable even when a plurality of devices exist.

As described above, in this embodiment, in a mobile network having a plurality of mobile router devices, a virtual address is used in the backbone network-side interface of the mobile router device, and the virtual redundant router protocol is activated on the mobile network-side interface. The virtual address of the network-side interface and its care-of address perform binding update processing, without increasing the load on the network, it is possible to provide a terminal device in a mobile network that does not install MobileIPv6 while moving between various access networks The ability to communicate.

Possibility of industrial use

As described above, in the present invention, when a plurality of mobile router devices connected to the mobile network and the access network are installed, the mobile router device to be used can be changed without increasing the load on the network. Therefore, Applicable to mobile network systems that use a certain network as a unit and move between different access networks.

Claims (18)

1. A mobile router device for accommodating one or more terminal devices and connecting a mobile network at a first location and a backbone network with said plurality of access routers through a first access router in a plurality of access routers, the mobile network moves within the backbone network by moving to a second location and connecting to a second access router of the plurality of access routers, It is characterized in that it has: A unit that determines whether the mobile router device used to connect the mobile network and the backbone network acts as a main router; recording a virtual address common to the mobile router devices belonging to said mobile networks located at the first and second locations, for said virtual address, means for generating a care-of-address available to the mobile router device at the second location; and means for generating and transmitting a binding update message in which the virtual address is associated with the care-of address when the mobile router device operates as the master router, in, the mobile network further includes backup router means, If the backup router device determines that the connection to the backbone network has been lost between the mobile router device and the first access router, the backup router device sends another binding update message including virtual address and the care-of address corresponding to the standby router device. 2. The mobile router device according to claim 1, wherein: The virtual address is assigned as a real address to any one of the mobile router devices belonging to the mobile network. 3. The mobile router device according to claim 1, characterized in that, it has: means for monitoring the quality of links connected to said backbone network; changing the unit used to determine the priority of the primary router and backup router according to the quality of the link; and Whether or not the mobile router operates as a unit of the master router is determined based on the priority. 4. The mobile router device according to claim 1, further comprising: When the mobile router device operates as the master router, means for storing the sequence number of the binding update message in a master router advertisement packet notifying the master router and transmitting the master router advertisement packet. 5. The mobile router device according to claim 4, wherein the master router advertisement packet uses a virtual router advertisement according to a virtual router redundancy protocol. 6. The mobile router device according to claim 4, wherein: The master router advertisement packet uses an IPv6 router advertisement message. 7. The mobile router device according to claim 1, further comprising: When the mobile router device operates as a backup router, A unit that receives a master router advertisement packet sent by another mobile router device, the master router advertisement packet notifying the mobile router device that the other mobile router device is working as a master router; A unit for recording the sequence number of the binding update message included in the received master router advertisement packet to use the sequence number when the mobile router device itself becomes a master router. 8. The mobile router device according to claim 7, wherein: The master router advertisement packet uses a virtual router advertisement according to a virtual router redundancy protocol. 9. The mobile router device according to claim 7, wherein: The master router advertisement packet uses an IPv6 router advertisement message. 10. A mobile network system, characterized in that it has: A plurality of mobile router devices as claimed in claim 1; at least one terminal device housed in said mobile router device; and A home agent device managing mobility of said mobile router device. 11. The mobile network system according to claim 10, characterized in that, The backbone network physical interface class of at least one mobile router device is different from the backbone network physical interface class of other mobile router devices. 12. The mobile network system according to claim 10, characterized in that, The same virtual address is used on the backbone network side of each mobile router device, the virtual redundant router protocol is implemented on the mobile network side, and when the mobile router device itself is the master router, communication is performed using the same virtual address. 13. The mobile network system according to claim 12, characterized in that, The mobile router serving as the main router sends a binding update message for mobility management using the same virtual address and a care-of address generated corresponding to the same virtual address to the home agent device. 14. A mobile router device, which is included in a mobile network system, the mobile network system comprising: one or more terminal devices; a mobile network, having a device for accommodating the terminal devices and connecting the mobile network to a backbone network a plurality of mobile router devices, the plurality of mobile router devices including a main router device and a backup router device; and a home agent device that associates a home address with a care-of address and manages the two addresses, It is characterized in that, the mobile network moves from a home network connected to a first location within the backbone network to a second location within the backbone network, When the main router at the first location still acts as the main router after the mobile network moves to the second location, the mobile router device associates the care-of address corresponding to the virtual address generated after moving to the second location with the associating a virtual address and registering the care-of-address to the home agent device, and If the backup router device determines that the connection to the backbone network has been lost between the primary router device and the backbone network, the backup router device sends a binding update message, which includes a virtual address corresponding to the primary router device and a corresponding another care-of-address of the backup router device. 15. The mobile router device according to claim 14, wherein: The virtual address is any one of physical addresses used at the backbone network side physical interface when each mobile router device belonging to the mobile network is connected to the home network. 16. The mobile router device according to claim 14, wherein: In order to notify the home agent device that the mobile router device acts as the master router, the master router advertisement packet sent to the mobile network contains the virtual address and another binding information sent to the home agent device. Specifies the sequence number of the update message. 17. The mobile router device according to claim 16, wherein: The primary router advertisement packet is a virtual router advertisement packet used by a virtual router redundancy protocol implemented on the mobile network side of the mobile router device. 18. The mobile router device of claim 16, wherein: The main router advertisement packet is an IPv6 router advertisement message sent to the mobile network side by the mobile router device operating as the main router.

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