JP2005184702A - Mobile ip network system, location registration information robustness improvement method, home agent, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile IP network system easily switching to an alternative home agent in a home agent fault. <P>SOLUTION: If a home agent 310 detects any fault, it informs an alternative home agent 320 of the fact by a fault notification device 316, and deletes a home agent address using an address re-setting device 315. The alternative home agent 320 confirms that other network devices do not use the home agent address, by an address re-setting device 325, and conducts re-setting of the home agent address, using the address re-setting device 325. According to the arrangement, the alternative home agent 320 operates as a substitute of the home agent 310. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a mobile IP network system, a method for improving the robustness of location registration information, a home agent, and a program, and in particular, a mobile IP network system in which a plurality of networks are connected via the Internet, and a method for improving the robustness of location registration information. , Home agents and programs.

The specification of mobile IP is proposed as an Internet draft of draft-ietf-mobileip-ipv6-24 in IETF (The Internet Engineering Task Force). This makes it possible for a mobile node moving on the IP network to move on the network while using the same IP address (home address).

Specifically, in a mobile IP network, mobility of a mobile node can be ensured by preparing a home agent and assigning an address (home address) that can be used fixedly by the mobile node.

Also, by providing each correspondent node with a mechanism for managing location registration information (home address and care of address) of the mobile node, the correspondent correspondent node can also communicate directly with the mobile node. .

FIG. 9 shows an example of a specific configuration of a conventional mobile IP network system.

Referring to FIG. 9, a conventional mobile IP network system includes a source network 100, a destination network 200, a network 300 connected to a home agent 310 (hereinafter referred to as a home network), and a mobile node 110. A network 400 (hereinafter referred to as a correspondent network) to which correspondent nodes 410 and 420 that communicate with each other are connected is configured to be connected to each other via the Internet. The source network 100 and the destination network 200 can be interchanged with each other and are given names for convenience.

The mobile node 110 is a terminal that moves and connects from the movement source network 100 to the movement destination network 200, generates an care-of address and sets it in the mobile node 110, and sends a location registration request to the home agent. A location registration request transmitting device 130 that transmits to 310, and a transmitted request management device 140 that manages transmitted location registration requests.

The address setting device 120 includes an address information acquisition unit 121 that acquires prefix information by obtaining a router advertisement that flows on the source network 100 and the destination network 200, and an address that generates a care-of address based on the prefix information. The generating unit 122 and the address setting unit 123 that sets a care-of address in the mobile node are configured.

A home agent 310 is connected to the home network 300. The home agent 310 receives a location registration request and registers location registration information in the location storage device 312, and a location storage that stores location registration information including a home address and a care-of address of the mobile node 110. Device 312.

Correspondent networks 400 are connected to correspondent nodes 410 and 420 that communicate with the mobile node 110.

The correspondent node 420 includes a location registration request receiving device 421 and a location storage device 422, similarly to the home agent 310.

Next, an operation in which the mobile node 110 performs communication in the conventional mobile IP network system will be described.

The mobile node 110 is about to move from the source network 100 to the destination network 200.

At this time, the mobile node 110 has a home address that does not change with movement in addition to the care-of address that can be used in the network 100 of the movement source. This home address is configured using prefix information of the home network 300 to which the home agent 310 is connected. The mobile node 110 uses a valid home address in the home network 300 when performing communication. As a result, the packet addressed to the mobile node 110 is delivered to the home network 300.

The home agent 310 registers the correspondence between the care-of address that the mobile node 110 can use in the source network 100 and the home address that the mobile node 110 can use in the home network 300 in the location storage device 312. As a result, it can be seen that the mobile node 110 actually exists in the movement source network 100, so that the home agent 310 captures the packet addressed to the mobile node 110 and the mobile node 110 exists on the movement source network 100. Forward to node 110.

In this way, the mobile node 110 can perform communication using the home address in the home network 300 even if it exists in a network other than the home network 300.

When the mobile node 110 moves from the movement source network 100 to the movement destination network 200, the location registration information existing in the position storage device 312 in the home agent 310 is updated, so that the same home in the movement destination network 200 is obtained. It becomes possible to receive a packet using the address.

That is, when the mobile node 110 moves between the source network 100 and the destination network 200, the location registration request transmission device 130 is used to transmit a location registration request to the home agent 310, and the location storage device 312. The location registration information existing in is updated. Since the packet addressed to the mobile node 110 is the home address in the home network 300, it is delivered to the home network 300 as described above. Then, the home agent 310 similarly transfers the data to the destination network 200.

As described above, the mobile node 110 performs communication using the home address in the home network 300, and thus continues to communicate with other network devices such as the correspondent node 410 while the mobile node 110 continues to communicate with the source network 100 and the destination network. It becomes possible to move between the networks 200.

As another means, by using the correspondent node 420 having the same location registration request receiving device 421 and the location storage device 422 as the home agent 310, the correspondent node 420 allows the mobile node 110 to be present in any network. Therefore, it is possible to directly communicate with the mobile node 110 without going through the home agent 310. In this case, the mobile node 110 notifies the location registration information not only to the home agent 310 but also the correspondent node 420 when moving between networks, and updates the location registration information in the location storage device 422.

Note that, as a conventional technique, there is an IP network in which a mobile node equipped with mobile IP and a mobile IP home agent are connected, and the home agent takes care of the mobile node when connecting to the external link of the mobile node. And means for transferring to the care-of address when receiving data addressed to the mobile node, the mobile node acquiring a new IP address at the destination, and the acquired care-of address to the home agent Call setting received by the mobile node in the mobile IP communication control system having means for notifying and means for notifying the source of the destination address acquired and means for transmitting a binding update for direct communication with the source Whether the data received with the request is highly real-time A communication control method in mobile IP that includes means for determining and means for transmitting a binding update to a transmission source in the case of data with high real-time property, and prevents delay of data with high real-time property in mobile IP. Yes (see Patent Document 1).

In addition, as a conventional technique, the mobile node generates a registration request packet for generating a registration request packet for registering the mobile node's coexistence care-of address (IPv6) with the home agent, and the mobile node's IPv4 address is the source address. And a registration request packet transmitting means for encapsulating and transmitting a registration request packet with IP route control information having the IPv4 address of the home agent as a destination address, and the network relay device transmits the IP route control information in the registration request packet. Source address conversion means for converting the source address in the IP address into the coexistence care-of address (IPv6), and enables mobile IP communication in an environment where IP networks using a plurality of versions of the IP protocol coexist. Like There is a mobile IP communication system (see Patent Document 2).

Furthermore, as a conventional technique, registration of mobile node location registration information is performed. The mobile node sends a location registration request to the foreign agent, and the foreign agent creates entry information of the mobile node and registers it in the visitor list. The index of the mobile node entry information in the visitor list is added to the location registration request and transferred to the home agent. The foreign agent creates the mobile node entry information in the visitor list based on the location registration request, and the foreign agent visits the visitor list. An index of mobile node entry information in the list is added to the location registration response and transferred to the foreign agent, and the foreign agent visits the index added to the location registration response. -There is a mobile IP data transfer method in which the data transfer rate is less likely to decrease even if the number of mobile nodes accommodated increases by adding it as storage location information to the entry information of the mobile node in the list (Patent Document 3, etc.) reference).

However, none of the conventional techniques has improved location registration robustness by multiplexing home agents.

That is, conventionally, in the mobile IP network system, the location storage device 312 in the home agent 310 and the location storage device 422 in the correspondent node 420 are used to cope with the mobility of the mobile node 110. The registration update operation for the storage devices 312 and 422 can only be performed by a registration procedure based on a location registration request transmitted from the mobile node 110 and by an internal deletion due to registration expiration. Therefore, there is currently no method other than changing the connection of the mobile node 110 to the network in order to explicitly update the location registration information. Therefore, for the purpose of improving the robustness of the location registration of the network, the location registration information existing in the home agent 310 in which the failure has occurred even when preparing an alternative home agent to be replaced when the home agent 310 fails. Cannot be easily registered with the newly added alternative home agent.
Japanese Patent Laid-Open No. 2001-144811 (page 4, FIG. 1) JP2003-018185 (page 5-7, FIG. 1) JP 2003-169773 (page 4-5, FIG. 1)

The conventional technology has the following problems.

The first problem is that the mobile node home agent cannot easily refer to or change the location registration information (home address and care-of address). The reason is that registration of the location registration information to the home agent must be performed by the mobile node itself. For example, when the home agent is to be restarted, the location registration information is saved and the home agent is restarted after the restart. This is because the flexible operation of registering the location registration information again by the administrator has not been easily realized.

The second problem is that all location registration information of a certain mobile node is managed by one home agent. For this reason, when a failure of the home agent occurs, it becomes impossible to communicate with the mobile node. Further, as pointed out in the first problem, it is difficult to refer to or change the location registration information of the mobile node, and it is difficult to prepare an alternative home agent.

In order to solve the above problems, an object of the present invention is to improve location registration robustness by multiplexing home agents that manage location registration information of mobile nodes in a mobile IP network system. It is to provide a method for improving the robustness of location registration information, a home agent, and a program.

The mobile IP network system of the present invention delegates management of location management information of a mobile node to an alternative home agent while minimizing the system outage when a mobile node home agent fails on the home network. It is characterized by that.

Also, the mobile IP network system of the present invention does not register location registration information from all mobile agents that are relatively distant from the network to all home agents when there are a plurality of home agents. The registration of only one home agent, and this home agent registers the location registration information with other home agents, so that the location registration information from the mobile node can be registered efficiently. Features.

Furthermore, the mobile IP network system of the present invention is a mobile IP network system in which a plurality of networks are connected via the Internet, moves between a source network and a destination network, generates a care-of address, and sets it A mobile node including an address setting device that performs transmission, a location registration request transmission device that transmits a location registration request to a home agent, and a transmitted request management device that manages a transmitted location registration request. A location storage device that stores location registration information including the home address and care-of address of the node, a location registration request reception device that receives a location registration request and registers location registration information in the location storage device, and location registration information from the location storage device Read position registration information reading device, position Location registration information writing device that writes location registration information to the storage device, address resetting device that deletes the home agent address of the home agent or resets the home agent address, and alternative home that the home agent has failed From the failure notification device for notifying the failure notification device of the agent, the home agent including the address information transmission / reception device for notifying the location registration information to the alternative home agent, and the home address and the care-of address of the mobile node connected to the home network A location storage device that stores location registration information, a location registration request reception device that receives a location registration request and registers location registration information in the location storage device, a location registration information reading device that reads location registration information from the location storage device, and a location storage Position registration on the device Location registration information writing device for writing information, an address resetting device that deletes the home agent address of the home agent or resets the home agent address, and an error notification device for an alternative home agent that indicates that a failure has occurred in the home agent A fault notification device for notifying a mobile station, an alternative home agent including an address information transmission / reception device for receiving notification of location registration information from the home agent, and a correspondent node connected to the correspondent network and communicating with the mobile node. And

Furthermore, the mobile IP network system of the present invention generates a care-of address by moving between a source network and a destination network in a mobile IP network system in which a plurality of networks are connected via the Internet. A mobile node including an address setting device to be set, a location registration request transmitting device for transmitting a location registration request to a home agent, and a transmitted request management device for managing a transmitted location registration request; and connected to a home network; A database device that manages location registration information, a location storage device that is connected to a home network and stores location registration information including a home address and a care-of address of a mobile node, a location storage device that receives a location registration request and stores location registration information Location registration to be registered in A solicitation receiving device, a location registration information reading device that reads location registration information from the location storage device, a location registration information writing device that writes location registration information to the location storage device, a home agent address of a home agent is deleted, or a home agent address is A home agent including an address resetting device to be set, a failure notification device for notifying the failure notification device of the alternative home agent that a failure has occurred in the home agent, and a database access device for writing location registration information in the database device; A location storage device that is connected to the home network and stores location registration information including the home address and care-of address of the mobile node, a location registration request reception device that receives location registration requests and registers location registration information in the location storage device, and location Memory Location registration information reading device that reads location registration information from location, location registration information writing device that writes location registration information to location storage device, address reset that deletes home agent address of home agent or resets home agent address Connected to the correspondent network and an alternative home agent including a failure notification device that notifies the failure notification device of the alternative home agent that a failure has occurred in the device, the home agent, and a database access device that reads location registration information from the database device And a correspondent node that communicates with the mobile node.

In the mobile IP network system of the present invention, the address setting device obtains prefix information by obtaining a router advertisement flowing on the network, and an address for generating a care-of address based on the prefix information. It is characterized by comprising generating means and address setting means for setting a care-of address in a mobile node.

On the other hand, the home agent of the present invention includes a location storage device that stores location registration information that includes a home address and a care-of address of a mobile node, and a location registration request that receives a location registration request and registers location registration information in the location storage device. Receiving device, location registration information reading device for reading location registration information from location storage device, location registration information writing device for writing location registration information to location storage device, and deleting home agent address or resetting home agent address The address resetting device, the failure notification device for notifying the failure notification device of the alternative home agent that a failure has occurred in the home agent, the location registration information is notified to the alternative home agent, and the location registration information is notified. Receiving address information transmitting / receiving device To.

The home agent of the present invention also includes a location storage device that stores location registration information that includes a home address and a care-of address of a mobile node, and a location registration request that receives a location registration request and registers location registration information in the location storage device. Receiving device, location registration information reading device for reading location registration information from location storage device, location registration information writing device for writing location registration information to location storage device, and deleting home agent address or resetting home agent address An address resetting device, a failure notification device for notifying the failure notification device of the alternative home agent that a failure has occurred in the home agent, and a database access device for writing location registration information to the database device and reading location registration information It is characterized by including.

On the other hand, in the method for improving the robustness of the location registration information according to the present invention, when the mobile node is connected to the network of the movement source, the step of performing the acquisition setting of the care-of address, and the mobile node homes the location registration request. Transmitting to the agent, the home agent receiving the location registration request and registering the location registration information, the home agent returning a location registration response to the mobile node, and the home agent receiving the location registration information. A step of notifying the alternative home agent, a step of registering the notified location registration information by the alternative home agent, a step of notifying the alternative home agent when the home agent detects a failure, and a home The agent deletes its home agent address and an alternate home address. The agent checks whether other network devices are using the home agent address used by the home agent, and when the alternative home agent confirms that the home agent address has been deleted by the home agent Re-setting the home agent address to the mobile node, when the mobile node moves through the network, performing the care-of-address acquisition setting, and transmitting the location registration request to the alternative home agent. The alternative home agent receives the location registration request and updates the location registration information, and the alternative home agent returns a location registration response to the mobile node.

Also, the location registration information robustness improving method of the present invention includes a step in which a mobile node makes a care-of-address acquisition setting when connected to a source network, and the mobile node sends a location registration request as a home. Transmitting to the agent, the home agent receiving the location registration request and registering location registration information, the home agent registering location registration information in the database device, and the home agent to the mobile node. A step of returning a location registration response; a step of notifying the home agent when the home agent detects a failure; a step of deleting the home agent address of the home agent; The process of reading the location registration information from the database device and the alternative home The agent writes the location registration information, the alternative home agent checks whether another network device is using the home agent address used by the home agent, and the alternative home agent The step of resetting the home agent address when it is confirmed that the home agent address has been deleted by the mobile node, the step of acquiring and setting the care-of address when the mobile node moves through the network, and the mobile node A step of transmitting a location registration request to the alternative home agent, a step of the alternative home agent receiving the location registration request and updating the location registration information, and a step of writing the location registration information into the database device by the alternative home agent. Alternative home Jento, characterized in that it comprises a step of returning a position registration response to the mobile node.

In addition, the program of the present invention causes a computer to store location registration information including a home address and a care-of address of a mobile node, and to receive a location registration request and register the location registration information in the location storage device. A location registration request receiving device, a location registration information reading device for reading location registration information from the location storage device, a location registration information writing device for writing location registration information to the location storage device, a home agent address being deleted or a home agent address The address resetting device, the failure notification device that notifies the failure notification device of the alternative home agent that a failure has occurred in the home agent, the location registration information to the alternative home agent, and the location registration Operates as an address information transmitter / receiver that receives information notifications Characterized in that to.

In addition, the program of the present invention includes a location storage device that stores location registration information that includes a home address and a care-of address of a mobile node, and a location that receives a location registration request and registers location registration information in the location storage device. A registration request receiving device, a location registration information reading device for reading location registration information from the location storage device, a location registration information writing device for writing location registration information to the location storage device, and deleting a home agent address or a home agent address An address resetting device for resetting, a failure notification device for notifying the failure notification device of the alternative home agent that a failure has occurred in the home agent, and a database for writing location registration information to the database device and reading location registration information To operate as an access device And butterflies.

The present invention provides a mechanism for enabling read / write operations from the outside with respect to location registration information stored in a home agent, which is fundamental in a mobile IP network system. Even when switching to an alternative home agent, the switching can be easily performed.

That is, in the mobile IP network system, as shown in FIG. 1, the home agents 310 and 320 are connected to the home network 300, the location registration information reading devices 313 and 323, and the location registration information document are connected to the home agents 310 and 320. Add-in devices 314 and 324 and address information transmitting / receiving devices 317 and 327 are added. Hereinafter, the home agent 320 is referred to as a substitute home agent 320 in the sense that the home agent 310 is substituted. Note that the home agent 310 and the alternative home agent 320 can be interchanged with each other and are given names for convenience.

As a result, the location registration information held from the active home agent 310 can be read and written to another alternative home agent 320. As described above, when the home agent 310 fails, another alternative home agent 320 can easily manage the location registration information in place of the home agent 310 in which the failure has occurred.

The first effect is that if a failure occurs in the home agent in an environment where mobile IP is used, there is a high possibility that the mobile node cannot communicate with other network devices. Sometimes an alternate home agent can immediately replace a failed home agent. As a result, it is possible to expect a reduction in communication disabled time between the mobile node and other network devices.

The second effect is that management of location registration information can be delegated to an alternative home agent while minimizing the system stoppage when the mobile node home agent fails on the network.

The third effect is that when there are a plurality of home agents, location registration information is not registered to all home agents from mobile nodes that are relatively distant from the network. The location registration information is registered only with the agent, and the home agent registers the location registration information with another home agent, whereby the location registration information from the mobile node can be efficiently registered.

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

Referring to FIG. 1, a mobile IP network system according to a first embodiment of the present invention includes a source network 100, a destination network 200, a home network 300 to which home agents 310 and 320 are connected, a mobile A correspondent network 400 to which a correspondent node 410 communicating with the node 110 is connected is configured to be connected to each other via the Internet.

The mobile node 110 is a terminal that moves and connects from the source network 100 to the destination network 200, and includes an address setting device 120, a location registration request transmission device 130, and a transmitted request management device 140. .

The address setting device 120 includes an address information acquisition unit 121 that acquires prefix information by obtaining a router advertisement flowing on the network 100 of the movement source, an address generation unit 122 that generates a care-of address based on the prefix information, The address setting unit 123 sets the address of the mobile node 110.

A home agent 310 and an alternative home agent 320 are connected to the home network 300.

The home agent 310 receives a location registration request and registers location registration information in the location storage device 312, and a location storage that stores location registration information including a home address and a care-of address of the mobile node 110. Deletes the device 312, the location registration information reading device 313 that reads location registration information from the location storage device 312, the location registration information writing device 314 that writes location registration information to the location storage device 312, and the home agent address of the home agent 310. An address resetting device 315 for resetting or resetting the home agent address, a failure notification device 316 for notifying the failure notification device 326 of the alternative home agent 320 that a failure has occurred in the home agent 310, and an alternative home agent 320 Composed of address information transmitting and receiving apparatus 317 Metropolitan notified of location registration information with a notification of the location registration information.

The alternative home agent 320 connects to the home network 300 as an alternative to the home agent 310. The alternative home agent 320 has the same configuration as that of the home agent 310, a location storage device 322 that stores location registration information including the home address and the care-of address of the mobile node 110, and a location registration request that receives location registration information. A location registration request receiving device 321 registered in the storage device 322; a location registration information reading device 323 that reads location registration information from the location storage device 322; and a location registration information writing device 324 that writes location registration information in the location storage device 322; The address resetting device 325 that deletes the home agent address of the alternative home agent 320 or resets the home agent address, and the failure notification device 316 of the home agent 310 that a failure has occurred in the alternative home agent 320 Do Detrimental notification device 326, and the address information transmitting and receiving apparatus 327 Metropolitan notified of location registration information with a notification of the location registration information to the alternate home agent 320.

A correspondent node 410 that communicates with the mobile node 110 is connected to the correspondent network 400.

Next, the operation of the mobile IP network system according to the first embodiment configured as described above will be described in detail with reference to FIG. 1, FIG. 2, and the sequence diagrams of FIG.

First, in order to perform communication, processing such as physically connecting a cable or turning on the apparatus is performed. Then, the mobile node 110 is connected to the source network 100 (step A1).

As a procedure to be performed first, the mobile node 110 obtains address information of the source network 100, generates a care-of address, and sets a care-of address using the address setting device 120 (step A2).

For this purpose, the address setting device 120 first obtains prefix information by obtaining a router advertisement flowing on the network 100 of the movement source by the address information obtaining unit 121 and cares based on the prefix information by the address generation unit 122. Of-address is generated and the care-of address is set in the mobile node 110 by the address setting means 123. This automatic setting method is published as RFC (Request for Comments) 2462 by the IETF. As a result, a care-of address that can be used by the mobile node 110 in the source network 100 can be set.

Next, when the mobile node 110 acquires and sets a care-of address that can be used in the source network 100, the mobile node 110 performs a procedure for registering location registration information (home address and care-of address) in the home agent 310. .

First, the mobile node 110 transmits a location registration request (packet) to the home agent 310 by the location registration request transmitting device 130 (step A3). At this time, the transmitted location registration request is managed by the transmitted request management device 140.

The home agent 310 receives the location registration request by the location registration request receiving device 311 and associates the home address that the mobile node 110 can use in the home network 300 with the care-of address acquired and set in the source network 100. Registration information is registered in the position storage device 312 (step A4).

When the registration of the location registration information is completed, the home agent 310 returns a location registration response to the mobile node 110 (step A5).

Thereafter, the correspondent node 410 connected to the correspondent network 400 can communicate with the mobile node 110 via the home agent 310 (step A6).

Next, the home agent 310 reads the location registration information from the location storage device 312 by the location registration information reading device 313, and notifies the alternative home agent 320 of the location registration information using the address information transmitting / receiving device 317 (step A7). ).

The alternative home agent 320 receives the location registration information notification from the address information transmitting / receiving device 327 and registers the location registration information in the location storage device 322 using the location registration information writing device 324 (step A8). As a result, the same location registration information is always registered in the home agent 310 and the alternative home agent 320.

When the home agent 310 detects some failure of the home agent 310 (step A9), the home agent 310 performs a procedure for causing the alternative home agent 320 to operate as the alternative.

First, the home agent 310 notifies the failure notification device 326 of the alternative home agent 320 that a failure has occurred in the home agent 310 by the failure notification device 316 (step A10).

Next, in order to interrupt the home agent function, the home agent 310 uses the address resetting device 315 to delete its own home agent address and invalidate its own home agent address (step S31). A11).

In the alternative home agent 320, the same location registration information as that already held by the home agent 310 is registered. When the alternative home agent 320 accepts the location registration request from the mobile node 110 instead of the home agent 310, the address resetting device 325 of the alternative home agent 320 sets the home agent address used by the home agent 310 to itself. It becomes possible by setting.

As processing for setting the home agent address by the address resetting device 325, the alternative home agent 320 first transmits a packet for confirming that the home agent address used by the home agent 310 is not used by another network device. (Step A12). If the home agent 310 has deleted its own home agent address, there is no such network device.

If there is a network device using the home agent address to be set, the alternative home agent 320 waits for an appropriate time and then repeats the confirmation.

If it is confirmed that the home agent 310 has deleted the home agent address, the alternative home agent 320 resets the home agent address by the address resetting device 325 (step A13).

Through the above procedure, the alternative home agent 320 can operate as an alternative to the home agent 310 (step A14).

When the mobile node 110 moves from the movement source network 100 to the movement destination network 200 (steps A15 and A16), the mobile node 110 is the first to be connected to the movement source network 100. As a procedure to be performed, the address setting device 120 performs acquisition setting of the care-of address (step A17). Note that details of the care-of-address acquisition setting are the same as in step A2, and a detailed description thereof will be omitted.

When a care-of address that can be used in the destination network 200 is acquired and set, the mobile node 110 performs a procedure for registering location registration information in the home agent 310.

First, the mobile node 110 transmits a location registration request (packet) to the home agent 310 by the location registration request transmitting device 130 (step A18).

The home agent 310 has already failed and no longer exists on the home network 300, and the location registration request is received by the alternative home agent 320 using the home agent address set in the home agent 310. .

The alternative home agent 320 receives the location registration request by the location registration request receiving device 321 and updates the location registration information existing in the location storage device 322 (step A19).

When the update of the location registration information is completed, the alternative home agent 320 returns a location registration response to the mobile node 110 (step A20).

Thereafter, the correspondent node 410 connected to the correspondent network 400 can communicate with the mobile node 110 via the alternative home agent 320 (step A21). At the same time, the location registration information reading device 323 reads the location registration information in the location storage device 322, and if it exists, notifies the location registration information to other alternative correspondent nodes.

In this way, a mobile IP network system that automatically performs a procedure that allows the alternative home agent 320 to register location registration information on behalf of the home agent 310 when a failure occurs in the home agent 310. realizable. This makes it possible to improve location registration robustness in the mobile IP network system.

In an environment where mobile IP is used, if a failure occurs in the home agent 310, the mobile node 110 is likely to be unable to communicate with other network devices. Since the alternative home agent 320 can immediately replace the failed home agent 310 in the event of a failure, it is possible to expect a reduction in the communication disabled time between the mobile node 110 and other network devices.

Further, when the home agent 310 of the mobile node 110 on the home network 300 fails, the management of the location registration information can be delegated to the alternative home agent 320 while minimizing the system stoppage.

Further, when there are a plurality of home agents 310 and 320, location registration information is not registered in all the home agents 310 and 320 from the mobile node 110 that is relatively distant from the network, but from the mobile node 110. Can register the location registration information from the mobile node 110 efficiently by registering with only one home agent 310 and registering the location registration information with the other home agent 320. it can.

Next, a second embodiment of the present invention will be described in detail with reference to the drawings.

In the mobile IP network system according to the second embodiment, the location registration information managed by the home agents 310 and 320 in the mobile IP network system according to the first embodiment is managed using an external database device 330. It is.

Referring to FIG. 4, the mobile IP network system according to the second embodiment of the present invention is a home in which a source network 100, a destination network 200, home agents 310 and 320, and a database device 330 are connected. The network 300 includes a correspondent network 400 to which a correspondent node 410 that communicates with the mobile node 110 is connected.

The mobile node 110 is a terminal that moves and connects from the source network 100 to the destination network 200, and includes an address setting device 120, a location registration request transmission device 130, and a transmitted request management device 140. .

The address setting device 120 includes an address information acquisition unit 121, an address generation unit 122, and an address setting unit 123.

A home agent 310, an alternative home agent 320, and a database device 330 are connected to the home network 300.

The home agent 310 receives a location registration request and registers location registration information in the location storage device 312, and a location storage that stores location registration information including a home address and a care-of address of the mobile node 110. Deletes the device 312, the location registration information reading device 313 that reads location registration information from the location storage device 312, the location registration information writing device 314 that writes location registration information to the location storage device 312, and the home agent address of the home agent 310. To the address resetting device 315 for resetting or resetting the home agent address, the failure notification device 316 for notifying the failure notification device 326 of the alternative home agent 320 that a failure has occurred in the home agent 310, and the database device 330. position And a database access unit 318 Metropolitan writing the recording information.

The alternative home agent 320 connects to the home network 300 as an alternative to the home agent 310. The alternative home agent 320 has the same configuration as that of the home agent 310, a location storage device 322 that stores location registration information including the home address and the care-of address of the mobile node 110, and a location registration request that receives location registration information. A location registration request receiving device 321 registered in the storage device 322; a location registration information reading device 323 that reads location registration information from the location storage device 322; and a location registration information writing device 324 that writes location registration information in the location storage device 322; The address resetting device 325 that deletes the home agent address of the alternative home agent 320 or resets the home agent address, and the failure notification device 316 of the home agent 310 that a failure has occurred in the alternative home agent 320 Do Detrimental notification device 326, and a database access unit 328 Metropolitan reading the registration information from the database apparatus 330.

A correspondent node 410 that communicates with the mobile node 110 is connected to the correspondent network 400.

Next, the overall operation of the mobile IP network system according to the second embodiment configured as described above will be described in detail with reference to FIG. 4, FIG. 5, and the sequence diagrams of FIG.

First, in order to perform communication, processing such as physically connecting a cable or turning on the apparatus is performed. Then, the mobile node 110 is connected to the movement source network 100 (step B1).

As a procedure to be performed first, the mobile node 110 obtains address information of the source network 100, generates a care-of address, and sets a care-of address using the address setting device 120 (step B2). Note that details of the care-of-address acquisition setting are the same as in step A2, and a detailed description thereof will be omitted.

Next, when the mobile node 110 acquires and sets a care-of address that can be used in the source network 100, the mobile node 110 performs a procedure for registering location registration information (home address and care-of address) in the home agent 310. .

First, the mobile node 110 transmits a location registration request (packet) to the home agent 310 by the location registration request transmitting device 130 (step B3). At this time, the transmitted location registration request is managed by the transmitted request management device 140.

The home agent 310 receives the location registration request by the location registration request receiving device 311 and associates the home address that the mobile node 110 can use in the home network 300 with the care-of address acquired and set in the source network 100. Registration information is registered in the position storage device 312 (step B4).

At the same time, the home agent 310 reads the location registration information existing in the location storage device 312 by the location registration information reading device 313 and registers it in the external database device 330 using the database access device 318 (step B5).

When the registration of the location registration information is completed, the home agent 310 returns a location registration response to the mobile node 110 (step B6).

Thereafter, the correspondent node 410 connected to the correspondent network 400 can communicate with the mobile node 110 via the home agent 310 (step B7).

When the home agent 310 detects some failure of the home agent 310 (step B8), the home agent 310 performs a procedure for causing the alternative home agent 320 to operate as the alternative.

First, the home agent 310 notifies the failure notification device 326 of the alternative home agent 320 that a failure has occurred in the home agent 310 by the failure notification device 316 (step B9).

Next, in order to interrupt the home agent function, the home agent 310 uses the address resetting device 315 to delete its own home agent address and invalidate its own home agent address (step S31). B10).

The alternative home agent 320 uses the database access device 327 and reads location registration information for managing address information from the database device 330 (step B11).

Next, the alternative home agent 320 registers the location registration information in the location storage device 322 using the location registration information writing device 324 (step B12).

Subsequently, the alternative home agent 320 uses the address resetting device 325 to set the same home agent address as the home agent address set in the home agent 310, thereby registering the location from the mobile node 110. The request is accepted on behalf of the home agent 310.

When resetting the address, the alternative home agent 320 first transmits a packet for confirming whether the network device using the home agent address to be set exists on the home network 300 (step B13). If the home agent 310 has deleted its own home agent address, there is no such network device.

If there is a network device using the home agent address to be set, the alternative home agent 320 waits for an appropriate time and then repeats the confirmation.

If it is confirmed that the home agent 310 has deleted the home agent address, the alternative home agent 320 resets the home agent address by the address resetting device 325 (step B14).

Through the above procedure, the alternative home agent 320 can operate as an alternative to the home agent 310 (step B15).

When the mobile node 110 moves from the movement source network 100 to the movement destination network 200 (steps B16 and B17), the mobile node 110 is the first to be connected to the movement source network 100. As a procedure to be performed, the address setting device 120 performs acquisition setting of the care-of address (step B18). Note that details of the care-of-address acquisition setting are the same as in step A2, and a detailed description thereof will be omitted.

When a care-of address that can be used in the destination network 200 is acquired and set, the mobile node 110 performs a procedure for registering with the home agent 310.

First, the mobile node 110 transmits a location registration request (packet) to the home agent 310 by the location registration request transmitting device 130 (step B19).

The home agent 310 has already failed and no longer exists on the home network 300, and the location registration request is received by the alternative home agent 320 using the home agent address set in the home agent 310. .

The alternative home agent 320 receives the location registration request by the location registration request receiving device 321 (step B19), and updates the location registration information existing in the location storage device 322 by the location registration information writing device 324 (step B20).

At the same time, the alternative home agent 320 reads the location registration information of the location storage device 322 to the location registration information reading device 323 and updates the location registration information of the external database device 330 using the database access device 327 (step B21). ).

When the update of the location registration information is completed, the alternative home agent 320 returns a location registration response to the mobile node 110 (step B22).

Thereafter, the correspondent node 410 connected to the correspondent network 400 can communicate with the mobile node 110 via the alternative home agent 320 (step B23).

As described above, according to the second embodiment, as in the first embodiment, it is possible to improve the robustness of location registration in the mobile IP network system. Further, in the second embodiment, the location registration information is also present in the database device 330 outside the home agent 310, so that even when the home agent 310 cannot transmit a failure notification as in step B9. The necessary location registration information can be taken out and an alternative home agent 320 can be prepared.

FIG. 7 is a block diagram showing the configuration of the mobile IP network system according to the third embodiment of the present invention. The mobile IP network system according to the present embodiment is different only in that a home agent program 340 is added to the home agents 310 and 320 of the mobile IP network system according to the first embodiment shown in FIG. Accordingly, other parts not specifically mentioned are denoted by the same reference numerals, and detailed description thereof is omitted.

The home agent program 340 is read by the home agents 310 and 320, and the operations of the home agents 310 and 320 are changed according to the location registration request receiving devices 311 and 321, the location storage devices 312 and 322, and the location registration information reading devices 313 and 323. The registered information writing devices 314 and 324, the address resetting devices 315 and 325, the failure notification devices 316 and 326, and the address information transmitting / receiving devices 317 and 327 are controlled. Since the operations of the home agents 310 and 320 under the control of the home agent program 340 are exactly the same as the operations of the home agents 310 and 320 in the first embodiment, detailed description thereof is omitted.

FIG. 8 is a block diagram showing the configuration of the mobile IP network system according to the fourth embodiment of the present invention. The mobile IP network system according to the present embodiment is different only in that a home agent program 350 is added to the home agents 310 and 320 of the mobile IP network system according to the second embodiment shown in FIG. Accordingly, other parts not specifically mentioned are denoted by the same reference numerals, and detailed description thereof is omitted.

The home agent program 350 is read by the home agents 310 and 320, and the operations of the home agents 310 and 320 are changed according to the location registration request receiving devices 311 and 321, the location storage devices 312 and 322, and the location registration information reading devices 313 and 323. Registration information writing devices 314 and 324, address resetting devices 315 and 325, failure notification devices 316 and 326, and database access devices 318 and 328 are controlled. Since the operations of the home agents 310 and 320 under the control of the home agent program 350 are exactly the same as the operations of the home agents 310 and 320 in the second embodiment, a detailed description thereof is omitted.

It is a block diagram which shows the structure of the mobile IP network system which concerns on Example 1 of this invention. FIG. 3 is a sequence diagram illustrating an operation of the mobile IP network system according to the first embodiment. FIG. 3 is a sequence diagram illustrating an operation of the mobile IP network system according to the first embodiment. It is a block diagram which shows the structure of the mobile IP network system which concerns on Example 2 of this invention. FIG. 10 is a sequence diagram illustrating an operation of the mobile IP network system according to the second embodiment. FIG. 10 is a sequence diagram illustrating an operation of the mobile IP network system according to the second embodiment. It is a block diagram which shows the structure of the mobile IP network system which concerns on Example 3 of this invention. It is a block diagram which shows the structure of the mobile IP network system which concerns on Example 4 of this invention. It is a block diagram which shows the structure of the conventional mobile IP network system.

Explanation of symbols

100, 200, 300, 400 Network 110 Mobile node 120 Address resetting device 121 Address information acquisition means 122 Address generation means 123 Address setting means 130 Location registration request transmission device 140 Transmitted request management device 310 Home agent 311 Location registration request reception device 312 Location storage devices 313 and 323 Location registration information reading devices 314 and 324 Location registration information writing devices 315 and 325 Address resetting devices 316 and 326 Fault notification devices 317 and 327 Address information transmitting and receiving devices 318 and 328 Database access devices 330 Database devices 340, 350 Home agent program 410, 420 Correspondent node 421 Location registration request receiving device 422 Location storage device

Claims (11)

Mobile IP characterized by delegating management of location management information of a mobile node to an alternative home agent while minimizing system outage when a mobile node home agent fails on a home network Network system. When there are multiple home agents, location registration information is not registered to all home agents from mobile nodes that are relatively distant from the network, but only one home agent is registered from the mobile node. The mobile IP network system is characterized in that location registration information from a mobile node is efficiently registered by the home agent registering location registration information with another home agent. In a mobile IP network system in which a plurality of networks are connected via the Internet,
An address setting device that moves between a source network and a destination network and generates and sets a care-of address, a location registration request transmission device that transmits a location registration request to a home agent, and a registered location registration A mobile node including a transmitted request management device for managing requests;
A location storage device that is connected to the home network and stores location registration information including the home address and care-of address of the mobile node, a location registration request reception device that receives location registration requests and registers location registration information in the location storage device, and location A location registration information reading device that reads location registration information from the storage device, a location registration information writing device that writes location registration information to the location storage device, and an address that deletes or resets the home agent address of the home agent A home agent including a resetting device, a failure notification device for notifying the failure notification device of the alternative home agent that a failure has occurred in the home agent, and an address information transmitting / receiving device for notifying location registration information to the alternative home agent;
A location storage device that is connected to the home network and stores location registration information including the home address and care-of address of the mobile node, a location registration request reception device that receives location registration requests and registers location registration information in the location storage device, and location A location registration information reading device that reads location registration information from the storage device, a location registration information writing device that writes location registration information to the location storage device, and an address that deletes or resets the home agent address of the home agent An alternative home agent including a resetting device, a failure notification device that notifies the failure notification device of the alternative home agent that a failure has occurred in the home agent, and an address information transmission / reception device that receives location registration information notification from the home agent;
A mobile IP network system comprising a correspondent node connected to a correspondent network and communicating with a mobile node. In a mobile IP network system in which a plurality of networks are connected via the Internet,
An address setting device that moves between a source network and a destination network and generates and sets a care-of address, a location registration request transmission device that transmits a location registration request to a home agent, and a registered location registration A mobile node including a transmitted request management device for managing requests;
A database device connected to the home network and managing location registration information;
A location storage device that is connected to the home network and stores location registration information including the home address and care-of address of the mobile node, a location registration request reception device that receives location registration requests and registers location registration information in the location storage device, and location A location registration information reading device that reads location registration information from the storage device, a location registration information writing device that writes location registration information to the location storage device, and an address that deletes or resets the home agent address of the home agent A home agent including a resetting device, a failure notification device for notifying the failure notification device of the alternative home agent that a failure has occurred in the home agent, and a database access device for writing location registration information in the database device;
A location storage device that is connected to the home network and stores location registration information including the home address and care-of address of the mobile node, a location registration request reception device that receives location registration requests and registers location registration information in the location storage device, and location A location registration information reading device that reads location registration information from the storage device, a location registration information writing device that writes location registration information to the location storage device, and an address that deletes or resets the home agent address of the home agent An alternative home agent including a resetting device, a failure notification device for notifying the failure notification device of the alternative home agent that a failure has occurred in the home agent, and a database access device for reading location registration information from the database device;
A mobile IP network system comprising a correspondent node connected to a correspondent network and communicating with a mobile node. The address setting device obtains prefix information by obtaining a router advertisement flowing on the network, address generation means for generating a care-of address based on the prefix information, and care-of address to the mobile node. 5. The mobile IP network system according to claim 3, comprising address setting means for setting. A location storage device for storing location registration information comprising a mobile node home address and a care-of address;
A location registration request receiving device that receives a location registration request and registers location registration information in a location storage device;
A location registration information reading device for reading location registration information from the location storage device;
A location registration information writing device for writing location registration information in the location storage device;
An address resetting device for deleting the home agent address or resetting the home agent address;
A failure notification device for notifying the failure notification device of the alternative home agent that a failure has occurred in the home agent;
A home agent comprising: an address information transmission / reception device that notifies location registration information to an alternative home agent and receives the location registration information notification. A location storage device for storing location registration information comprising a mobile node home address and a care-of address;
A location registration request receiving device that receives a location registration request and registers location registration information in a location storage device;
A location registration information reading device for reading location registration information from the location storage device;
A location registration information writing device for writing location registration information in the location storage device;
An address resetting device for deleting the home agent address or resetting the home agent address;
A failure notification device for notifying the failure notification device of the alternative home agent that a failure has occurred in the home agent;
A home agent comprising: a database access device that writes location registration information to a database device and reads location registration information. When the mobile node is connected to the source network, a process for setting acquisition of care of address;
A mobile node sending a location registration request to a home agent;
A step in which a home agent receives a location registration request and registers location registration information;
The home agent returns a location registration response to the mobile node;
A step in which the home agent notifies the alternative home agent of the location registration information;
An alternative home agent registering the notified location registration information;
When the home agent detects a failure, notifies the alternative home agent to that effect;
The home agent deletes its own home agent address;
An alternative home agent confirming whether another network device is using the home agent address used by the home agent;
The alternative home agent resetting the home agent address when the home agent confirms that the home agent address has been deleted by the home agent;
When the mobile node moves through the network, the process of setting acquisition of care of address;
A mobile node sending a location registration request to an alternative home agent;
An alternative home agent receiving a location registration request and updating location registration information;
A method for improving the robustness of location registration information, comprising: a step of an alternative home agent returning a location registration response to a mobile node. When the mobile node is connected to the source network, a process for setting acquisition of care of address;
A mobile node sending a location registration request to a home agent;
A step in which a home agent receives a location registration request and registers location registration information;
A step in which the home agent registers the location registration information in the database device;
The home agent returns a location registration response to the mobile node;
When the home agent detects a failure, notifies the alternative home agent to that effect;
The home agent deletes its own home agent address;
An alternative home agent reading location registration information from the database device;
An alternative home agent writing location registration information;
An alternative home agent confirming whether another network device is using the home agent address used by the home agent;
The alternative home agent resetting the home agent address when the home agent confirms that the home agent address has been deleted by the home agent;
When the mobile node moves through the network, the process of setting acquisition of care of address;
A mobile node sending a location registration request to an alternative home agent;
An alternative home agent receiving a location registration request and updating location registration information;
An alternative home agent writing location registration information to the database device;
A method for improving the robustness of location registration information, comprising: a step of an alternative home agent returning a location registration response to a mobile node. A location storage device that stores location registration information including a home address and a care-of address of a mobile node; a location registration request reception device that receives a location registration request and registers location registration information in the location storage device; Location registration information reading device that reads location registration information from the device, location registration information writing device that writes location registration information to the location storage device, and address reset that deletes the home agent address or resets the home agent address A failure notification device for notifying the failure notification device of the alternative home agent that a failure has occurred in the home agent, and an address information transmission / reception device for notifying location registration information to the alternative home agent and receiving notification of location registration information Program to operate as. A location storage device that stores location registration information including a home address and a care-of address of a mobile node; a location registration request reception device that receives a location registration request and registers location registration information in the location storage device; Location registration information reading device that reads location registration information from the device, location registration information writing device that writes location registration information to the location storage device, and address reset that deletes the home agent address or resets the home agent address A program for operating as a device, a failure notification device for notifying a failure notification device of an alternative home agent that a failure has occurred in a home agent, and a database access device for writing location registration information to the database device and reading location registration information .

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