JP4334318B2 - Mobile IP communication system, management device and apparatus in mobile IP communication system, and mobile IP communication method - Google Patents

Description

  The present invention relates to a mobility control network architecture that provides mobility of communication by registering current location information with a location management node.

  There are a dynamic HA allocation method (1) and a dynamic HA assignment method (2) as a concept and technology for changing the home agent (HA) that manages the location of the MN as the mobile node (MN) moves.

  In the case of (1), the MN broadcasts a location registration message to the connected segment, recognizes the server (node) that responds to it as HA, and registers the location with that server (node) again. To do.

On the other hand, in the case of (2), a location registration message is transmitted to the HA (hereinafter also referred to as “old HA”) stored in the MN, and old
The HA is dynamically allocated by transferring it to a new HA (hereinafter also referred to as “new HA”).
"Mobile IPv4 Dynamic Home Agent Assignment Framework", co-authored by M. Kulkarni, A. Patel, K. Leung, 17 October 2003

  In the dynamic HA allocation method, there is a problem that redundant traffic is generated by the broadband of the location registration message, and a delay occurs until the HA is recognized.

  In the dynamic HA assignment method, a specific method for determining a new HA has not been determined.

  According to the present invention, when a device, for example, MN or HA has a list indicating the HA to be registered for the care-of address (CoA), the HA is dynamically assigned by referring to the list when registering the location. Thus, an object of the present invention is to provide a communication system that can solve the above problems.

  An object of the present invention is to provide a management apparatus having list management means for managing a list in which network domains and location information of home agents are associated with each other and list sending means for sending at least part of the list in mobile IP communication A list receiving unit that receives a list from the management device, a home agent selecting unit that compares the care-of address of the device with a network domain in the received list, and acquires location information of the corresponding home agent, and the acquisition This is achieved by a mobile IP communication system comprising a communication terminal having location registration means for performing location registration with the home agent based on the location information of the home agent.

  Another object of the present invention is to provide list management means for managing a list in which IP addresses are associated with home agent location information and list sending means for sending at least a part of the list in mobile IP communication. A management device, a list receiving means for receiving a list from the management device, a home agent selection means for comparing the self-care-of address with an IP address in the received list, and acquiring position information of the corresponding home agent; The present invention is also achieved by a mobile IP communication system comprising a communication terminal having a location registration means for performing location registration with the home agent based on the acquired location information of the home agent.

  According to the present invention, the communication terminal can know the location information of the home agent (HA) to be location-registered in correspondence with the network domain and the IP address. Therefore, even when a route switching (handoff) across network domains is performed, by referring to the list held by the communication terminal, the location information of the HA after switching is not inquired of the management device every time switching is performed. It is possible to obtain the information and realize quick switching and reduce the traffic generated by the inquiry processing.

  What is sent by the list sending means may be the whole list, a part of the list, or a network domain or IP address associated with HA location information.

  In a preferred embodiment, the communication terminal is configured to request the management apparatus to send the list periodically and / or in a predetermined case. Alternatively, the management apparatus may be configured to broadcast the list to communication terminals that are in communication regularly and / or in a predetermined case.

  Another object of the present invention is to provide a list management means for managing a list in which network domain and home agent location information are associated with each other, and a management apparatus having a list sending means for sending at least a part of the list, In a mobile IP communication system comprising a communication terminal, a list receiving means for receiving a list sent from the list sending means, a care-of address from the communication terminal, and a network domain in the received list are compared, Home agent selection means for acquiring position information of a corresponding home agent, and position information transmission means for transmitting the acquired position information of the home agent to the communication terminal in order to register the position information in the communication terminal. Mobile IP communication system characterized by comprising apparatus It is also achieved by.

  Another object of the present invention is to provide a management device having a list management means for managing a list in which an IP address is associated with location information of a home agent, and a list sending means for sending at least a part of the list; In a mobile IP communication system comprising a communication terminal, a list receiving means for receiving a list sent from the list sending means, a care-of address from the communication terminal, and an IP address in the received list are compared, Home agent selection means for acquiring position information of a corresponding home agent, and position information transmission means for transmitting the acquired position information of the home agent to the communication terminal in order to register the position information in the communication terminal. Also achieved by a mobile IP communication system characterized by comprising a device. That. In these inventions, it is desirable that the home agent functions as the device. Of course, it goes without saying that a device other than the home agent can function as the device.

  In a preferred embodiment, the device is configured to request the management device to send the list periodically and / or in certain cases. Alternatively, the management device may be configured to distribute the list to the device periodically and / or in a predetermined case.

  Further, an object of the present invention is to provide at least a part of a list to the communication terminal in the mobile IP communication system according to claim 1 or 2 of the claims of the present invention. Is also achieved. Alternatively, an object of the present invention is to provide a location of a home agent to be registered by a communication terminal with reference to a list received from the management device in the mobile IP communication system according to claim 5 or 6. It is also achieved by an apparatus characterized by transmitting information to the communication terminal.

  Furthermore, an object of the present invention is to provide a list management step for managing a list in which a network domain and location information of a home agent are associated with each other in mobile IP communication, and list sending for sending at least a part of the list. A list receiving step of receiving a list from the management device in the communication terminal, and comparing the care-of address of the device with the network domain in the received list to obtain the location information of the corresponding home agent The present invention is also achieved by a mobile IP communication method comprising an agent selection step and a location registration step of performing location registration with the home agent based on the acquired location information of the home agent.

  Alternatively, an object of the present invention is to provide a list management step for managing a list in which an IP address and location information of a home agent are associated with each other in mobile IP communication, and list sending for sending at least a part of the list. A list receiving step for receiving a list from the management device in the communication terminal, and comparing the care-of address of the device with the IP address in the received list to obtain the location information of the corresponding home agent The present invention is also achieved by a mobile IP communication method comprising an agent selection step and a location registration step of performing location registration with the home agent based on the acquired location information of the home agent.

  In another embodiment, a management device having a list management means for managing a list in which a network domain and home agent location information are associated, a list sending means for sending at least a part of the list, and a communication terminal A mobile IP communication method comprising: a list receiving step of receiving a list sent from the management device in a device connectable to the management device and the communication terminal; A home agent selection step of comparing the address with the network domain in the received list and acquiring the location information of the corresponding home agent; and for registering the location information in the communication terminal, Location to send location information to the communication terminal And a multi-address transmission step.

  In yet another embodiment, a management apparatus comprising: a list management unit that manages a list in which an IP address is associated with location information of a home agent; and a list transmission unit that transmits at least a part of the list; In a mobile IP communication system including a terminal, a mobile IP communication method includes: a list receiving step of receiving a list sent from the management device in a device connectable to the management device and the communication terminal; A home agent selection step of comparing the care-of address with the IP address in the received list to acquire the position information of the corresponding home agent, and the acquired home agent to register the position information in the communication terminal The location information transmission channel for transmitting the location information to the communication terminal. Tsu and a flop.

  According to the present invention, even when a route switching (handoff) across a network domain is performed, the management device stores the HA location information after switching by referring to the list held by the communication terminal. Can be acquired without inquiring, and quick switching can be realized, and the traffic generated by the inquiry processing can be reduced. Further, for example, when the HA holds the list, it is possible to realize quick switching without inquiring of the management apparatus, and to reduce the traffic generated in the inquiry processing.

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing an outline of a network architecture according to the first embodiment of the present invention. As shown in FIG. 1, in the network architecture according to the present embodiment, a plurality of home agents (HA) 12-1, 12-2,..., And an HA list management server 14 are connected to a network 10. ing. Each HA 12 has a foreign agent (“FA” in the figure).
Are connected to each other. In such a network architecture, the mobile node (MN), which is a mobile terminal, can receive a packet from the correspondent node (CN) by performing location registration with the HA 12, as will be described later.

  As shown in FIG. 2 (a), the HA list management server 14 according to the present embodiment includes, for each network domain, an HA allocation list 28 indicating the HA to be registered by the MN located in the network domain, and the HA And a list distribution unit 30 that executes an allocation list distribution process.

  As shown in FIG. 3, the HA 12 includes a location registration control unit 32, a location registration management unit 34, a tunneling processing unit 36, a location registration unit 40, a location registration DB 42, a home address (HoA) generation unit 44, and an HA list management server 14. A list receiving unit 46 for receiving the HA allocation list 54 and a list holding unit 48 for holding the received list. Further, as will be described later, after receiving the care-of address (CoA) from the MN, the list is referenced by referring to the list, and the HA that notifies the MN of the location information of the HA, and the HA refers to the location information of the HA. A position information notification unit 56 is provided.

  Each HA is arranged in various layers set in the network topology. For example, it may be located in a hierarchy called a mobile terminal base station, or may be located in a hierarchy called an office building. As will be described in detail later, the MN registers a position with any HA based on its own position. That is, in the present embodiment, the HA functions as a local location registration server.

As shown in FIG. 2B, the MN 22 includes a location registration control unit 62, a location registration unit 64, a list reception unit 66, and a list holding unit 68.
The location registration control unit 62 determines and manages to which HA the MN is registered.
The list receiving unit 66 receives the HA allocation list 72 from the HA list management server 14 and holds the list received by the list holding unit 68. Furthermore, based on its own care-of address (CoA), the list is referred to by referring to the list, and the location information of the HA to which the MN should register the location from a certain HA, and the list reference unit 70 that identifies the HA to which the MN should register the location. HA position information receiving unit 74 for receiving.

The packet transmission from the CN to the MN in the network architecture configured as described above will be described.
As shown in FIG. 4, the MN 22 is turned on in a segment 411 among management targets (reference numeral 410) of a certain HA 12-1 (hereinafter also referred to as “HA (# 1) 12-1”). (Step 401). It may be when the MN moves from another HA management target in a state where the session is interrupted.

  In the example of FIG. 4, when the terminal MN is powered on, the terminal MN receives the agent advertisement broadcasted by the FA (# 1) (step 402) and acquires a new care-of address (CoA) “AAA”. . At the same time, it recognizes that it is connected to the network managed by the new HA.

In addition, the terminal MN can recognize the HA to be registered when the power is turned on by making an inquiry to a management server (not shown) that manages the HA location information, referring to the internal memory, and the like.
The MN 22 requests the HA (# 1) 12-1 to register the location of the IP address “AAA” (step 403). The HA (# 1) 12-1 generates a home address (HoA) “XXX” corresponding to the received IP address “AAA”, and registers the IP addresses “AAA” and “XXX” in association with the location registration DB 42. (Step 404).

Next, consider a case where the correspondent node (CN) 50 tries to transmit a packet to the MN 22.
The CN 50 transmits the packet to the IP address “XXX” (steps 405 and 406). Here, in the packet, “dst = XXX,
src = CN ".

The packet is received by the HA (# 1) 12-1, and the HA (# 1) 12-1 refers to the location registration DB 42 and tunnels to the IP address “AAA” (step 407) to deliver the packet to the MN 22. It becomes possible.
In the present embodiment, the HA list management server 14 sends the HA allocation list to the MN 22 (step 408). FIG. 6 is a diagram showing an example of the HA allocation list according to the present embodiment. As shown in FIG. 6, the HA allocation list describes the corresponding HA IP address for each segment (network domain).

  The HA list management server 14 may send the entire HA allocation list to the MN, or may send a portion of the list including the range of a predetermined segment and the corresponding IP address of the HA to the MN. Alternatively, only the HA IP address corresponding to the segment where the MN is located may be sent to the MN. Hereinafter, an entire list, a list portion, or a combination of a segment and an IP address is collectively referred to as a “list”. The list is referred to when the MN registers the location with the HA, which will be described in detail later.

  Next, a case where the MN 22 moves to another segment 412 in the management target (see reference numeral 410) of the same HA (# 1) 12-1 will be described. This movement is sometimes referred to herein as “micro movement”.

  As shown in FIG. 5, when the MN 22 moves to another segment 412 (step 501), the MN 22 refers to the received list (step 502), and sets a new care-of address (CoA) and a segment ( Network domain), identify the IP address of the HA associated with the segment to which it belongs, and request location registration for that HA. In the example of FIG. 5, as a result of referring to the list, the MN recognizes the HA (# 1) as the HA to be registered, and requests the HA (# 1) to register the location of the IP address “BBB” (step 503). The HA (# 1) 12-1 refers to the location registration DB 42, rewrites the IP address “AAA” with the IP address “BBB”, and registers the IP address “BBB” and the home address (HoA) “XXX” in association with each other. (Step 504).

When the CN 50 transmits a packet to the MN 22, the following operation is performed.
The CN 50 transmits the packet to “dst = XXX, src = CN” (steps 505 and 506).
A packet addressed to “XXX” from the CN is received by the HA (# 1) 12-1. Since HA (# 1) 12-1 knows that the current IP address of MN 22 is “BBB”, it tunnels the packet to address “BBB” (step 507). In this way, the MN 22 can reliably receive a packet without interruption of the session even when moving to another segment managed by the same HA (micro movement).

  Next, the case where the MN 22 moves to a segment that is managed by another HA (HA (# 2) 12-2) will be described with reference to FIG. This movement is also referred to as “macro movement”.

  When the MN moves to a segment under the jurisdiction of the HA (# 2) 12-2 (step 701), the MN 22 refers to the list (step 702), and sets a new care-of address (CoA) and a segment in the list. (Network domain) is compared, the IP address of the HA associated with the segment to which it belongs is specified, and location registration is requested to the HA. In the example of FIG. 7, as a result of referring to the list, location registration is requested to the HA (# 2) 12-2 (step 711). In response to the location registration request, HA (# 2) 12-2 generates a home address (HoA) “YYY” corresponding to the new IP address “CCC” of the MN 22, and stores the IP address in the location registration DB 42. “YYY” and “CCC” are registered in association with each other (step 712).

  When the MN 22 moves during communication, the MN 22 registers the new IP address “CCC” in the HA (# 1) 12-1 (step 703), thereby realizing packet transmission without interrupting the session. It becomes possible. After the communication is completed, the location registration is performed in the HA (# 2) 12-2 by the above-described processing, and the location information of the HA (# 1) 12-1 is deleted.

Next, when the CN 50 transmits a packet to the MN 22, the following operation is performed.
The CN 50 transmits the packet to “dst = YYY, src = CN” (steps 704 and 705).
The packet addressed to “YYY” from CN is received by HA (# 2) 12-2. HA (# 2) 12-2 knows that the current IP address of MN 22 is “CCC”, and tunnels the packet to address “CCC” (step 706). In this way, the MN 22 can reliably receive a packet without interruption of a session even when moving to a segment (macro movement) that is a management target of another HA.

  As described above, according to the present embodiment, all, a part, or a predetermined segment of the HA allocation list in which the HA IP address corresponding to each segment (network domain) is associated from the HA list management server. And the HA's IP address are sent to the MN. Therefore, the MN can know the HA to be registered by referring to the received list. Therefore, even if a segment (network domain) is assigned to a building or a specific area, and the MN located in that segment should register the location with the HA of another segment, it can know the HA. As a result, appropriate location registration is possible.

  In the above embodiment, the list is distributed from the HA list management server to the MN at the time of initial MN location registration, such as when the power is turned on, but the list distribution timing is not limited to this. Absent. For example, the MN may ask the HA list management server to distribute the list when the power is turned on or when the memory of the MN is cleared. Alternatively, the MN may periodically request distribution of the list from the HA list management server. The HA list management server is notified of information such as the IP address of the newly installed HA, the change of the IP address of the HA, and the change of the segment (network domain) to be grasped. Based on this, the HA allocation list is generated. Has been updated. Therefore, as described above, when the MN appropriately receives a new list, the MN can also register a location with an appropriate HA according to the updated list.

  Alternatively, in place of or in addition to the MN requesting the list distribution, the HA list management server may periodically broadcast the HA allocation list to the connected MN. . Further, instead of or in addition to periodic distribution, the HA list management server broadcasts the HA allocation list to the MN when data in the HA allocation list is added, updated, or deleted. May be.

  In the above embodiment, the MN is configured to hold a list distributed from the HA list management server and refer to this list. This prevents the MN from accessing the HA list management server every time the segment changes. The server that manages the HA location information is not limited to the HA list management server, and may be a management server (not shown). Further, the present invention is not limited to this, and after identifying the HA IP address using the list to which the MN is distributed, it may be discarded without being stored. In this case, the MN needs to request distribution of the list every time it is necessary, but since it is not necessary to store the list in the MN, it is possible to reduce the required memory capacity.

  Next, a second embodiment of the present invention will be described. In the first embodiment, the MN is configured to acquire the whole or part of the HA allocation list from the HA list management server. However, in the second embodiment, the HA is in the HA state. An HA allocation list is held in the storage device, and necessary information can be given to the MN.

  As shown in FIG. 8, in this embodiment, the HA periodically requests distribution of the HA allocation list from the HA list management server 14 and stores the distributed list (steps 800-a, 800-). b). For example, when the MN 22 located in the segment under the jurisdiction of the HA (# 1) 12-1 moves to another HA (eg, the segment under the jurisdiction of the HA (# 2) 12-2, that is, moves macroly. In this case (step 801), the new care-of address (CoA) of the MN 22 is transmitted from the MN 22 to the HA (# 1) 12-1 (step 802). In response, the received new care-of address (CoA) is compared with the segment (network domain) in the HA assignment list, and the location information (IP address) of the HA to be registered by the MN is selected. (# 1) 12-1 transmits the position information of the selected HA (in this case, HA (# 2) 12-2) to the MN (step 803) The MN 22 refers to the received position information of the HA. The HA (HA (# 2) 12-2 Location registration to the propagation path of data from (step 804) .CN is the same as in the first embodiment.

  In the second embodiment, when the MN is powered on or in the initial operation, the MN acquires the location information (IP address) of the HA to be registered, and manages the location information of the HA. To the management server (not shown). In some cases, the management server is the HA list management server 14.

  Further, in the original HA (HA (# 1) 12-1), after transmitting the location information of the selected HA to the MN, the connection with the MN may be disconnected. Thereby, it is possible to suppress the number of MNs that the HA has jurisdiction over. It is also possible to avoid a situation where there are a plurality of HAs connected to the MN.

  As in the second embodiment, the HA allocation list may be periodically requested to be distributed to the HA list management server as in the second embodiment. Alternatively, the HA list management server may periodically broadcast the HA allocation list to the HA instead of the HA requesting the list distribution or in addition to requesting the list. Further, instead of or in addition to periodic distribution, the HA list management server broadcasts the HA allocation list to the HA when data in the HA allocation list is added, updated, or deleted. May be.

The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.
For example, in the above embodiment, the HA allocation list may be in a table format. In the above embodiment, the IP address is used as the HA position information, but other information can be used.

  In the first embodiment, the HA allocation list associates a segment (network domain) with the IP address of the HA that has jurisdiction over the segment, the MN's care-of address (CoA), and the HA allocation. The list segment (network domain) is being compared. However, the present invention is not limited to this. In the HA allocation list, an IP address is associated with an IP address of an HA to be registered by the MN having the IP address, and by comparing the IP addresses, The configuration may be such that the IP address of the HA to be registered by the MN is selected.

FIG. 1 is a block diagram showing an outline of a mobile IP communication system according to an embodiment of the present invention. 2A is a block diagram showing the configuration of the HA list management server according to the present embodiment, and FIG. 2B is a block diagram showing the configuration of the MN according to the present embodiment. FIG. 3 is a block diagram showing the configuration of the HA according to the present embodiment. FIG. 4 is a diagram for explaining an example of processing executed by the HA, MN, HA list management server, etc., and data transmission between these in the first embodiment. FIG. 5 is a diagram for explaining another example of processing executed in the HA, MN, HA list management server, and the like and data transmission between them in the present embodiment. FIG. 6 is a diagram showing an example of the HA allocation list according to the present embodiment. FIG. 7 is a diagram for explaining still another example of processing executed by the HA, MN, HA list management server, and the like, and data transmission between these in this embodiment. FIG. 8 is a diagram for explaining an example of processing executed by the HA, MN, HA list management server, etc., and data transmission between these in the second embodiment.

Explanation of symbols

12 Home Agent (HA)
14 HA list management server 22 Mobile node (MN)
50 Correspondent Node (CN)

Claims (7)

Mobile IP comprising: a list management means for managing a list in which a network domain and location information of a home agent are associated; a management apparatus having a list sending means for sending at least a part of the list; and a communication terminal In a communication system,
List receiving means for receiving the list sent from the list sending means;
Home agent selection means for comparing the care-of address from the communication terminal with the network domain in the received list and obtaining the location information of the corresponding home agent;
A mobile IP communication system comprising: an apparatus having position information transmitting means for transmitting the acquired position information of a home agent to the communication terminal in order to register position information in the communication terminal. Mobile IP comprising: a list management means for managing a list in which an IP address is associated with location information of a home agent; a management apparatus having a list sending means for sending at least a part of the list; and a communication terminal In a communication system,
List receiving means for receiving the list sent from the list sending means;
Home agent selection means for comparing the care-of address from the communication terminal with the IP address in the received list and obtaining the location information of the corresponding home agent;
A mobile IP communication system comprising: an apparatus having position information transmitting means for transmitting the acquired position information of a home agent to the communication terminal in order to register position information in the communication terminal.   3. The mobile IP according to claim 1, wherein the device is configured to request the management device to send the list periodically and / or in a predetermined case. 4. Communications system.   The mobile IP communication according to claim 1 or 2, wherein the management device is configured to distribute the list to the device periodically and / or in a predetermined case. system. The mobile IP communication system according to claim 1 or 2,
The mobile communication IP system, wherein the device refers to the list received from the management device, and transmits to the communication terminal location information of a home agent to be registered by the communication terminal. Mobile IP comprising: a list management means for managing a list in which a network domain and location information of a home agent are associated; a management apparatus having a list sending means for sending at least a part of the list; and a communication terminal In a communication system,
In the device connectable with the management device and the communication terminal,
A list receiving step of receiving a list sent from the management device;
A home agent selection step of comparing the care-of address from the communication terminal with the network domain in the received list and obtaining the location information of the corresponding home agent;
A mobile IP communication method comprising: a location information transmission step of transmitting the acquired location information of the home agent to the communication terminal in order to register location information in the communication terminal. Mobile IP comprising: a list management means for managing a list in which an IP address is associated with location information of a home agent; a management apparatus having a list sending means for sending at least a part of the list; and a communication terminal In a communication system,
In the device connectable with the management device and the communication terminal,
A list receiving step of receiving a list sent from the management device;
A home agent selection step of comparing the care-of address from the communication terminal with the IP address in the received list and obtaining the location information of the corresponding home agent;
A mobile IP communication method comprising: a location information transmission step of transmitting the acquired location information of the home agent to the communication terminal in order to register location information in the communication terminal.

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