JP2011055236A - Communication system, mapping information notification device, mapping information notification method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently perform optimization of a communication path when an end terminal or an ID is moved in an ID separation network which separately treats a locator and the ID. <P>SOLUTION: This mapping information notification device holds a lookup table for associating a set of a transmission source ID and a transmission destination ID of a packet with a transmission source locator of the packet, and when mapping information between the transmission destination ID and the transmission destination locator is changed, extracts the transmission source locator associated with the transmission destination ID by referring to the lookup table, and notifies a packet repeater included in the transmission source locator of the changed contents of the mapping information. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a communication system, a mapping information communication apparatus, a mapping information notification method, and a program, and in particular, a communication system, a mapping information notification apparatus, and a mapping information communication method based on an architecture that handles an identifier of a communication terminal and a locator of the communication terminal separately. And the program.

  On the Internet, packets fly over networks that span the world. The Internet realizes a global network based on a TCP / IP network. In particular, the Internet enables a global network by forming an IP network based on IP (Internet Protocol). IP is a protocol (ie, protocol) in communication, and handles the location (position) of a communication terminal. Like an actual land or building, an IP network can uniquely identify a location, so that communication terminals around the world can communicate with each other by knowing the location of the partner terminal with which they want to communicate. it can. That is, the value indicating the location in the IP is called an IP address because it serves as an address (address) indicating the actual land or building.

  In the current Internet, it is difficult to move a communication terminal freely, and there is a problem that route information indicating a communication route to a destination IP address is increasing. The cause of these problems lies in the characteristics and role of IP addresses in the current Internet. In an IP network forming the current Internet, an IP address serves as a value indicating which location a communication terminal is, and also serves as an identifier for uniquely identifying the communication terminal. In other words, when compared to an actual address, the IP address indicates the address of the building and also the name of the person living in the building (or the name of the building). Therefore, since the address and the name of the resident are associated with each other, when the building where the resident resides is changed, the name of the resident must also be changed.

  In the current IP network, due to such features and roles of IP addresses, not only the address in communication changes every time the communication terminal connects to a different network, but also the identifier that uniquely identifies the communication terminal changes at the same time. If the identifier of the communication terminal is changed during communication, the communication is disconnected, which makes it difficult to move the network of the communication terminal during communication.

  In the current Internet, route information of IP addresses of other networks (network B) may be sent to a certain network (network A) for the purpose of securing a redundant communication route that is resistant to communication failures. Then, the route information managed by the network A includes both the IP address of the network A and the IP address of the network B, and the route information increases. In the current Internet, the increased route information is also propagated to downstream networks after the network A, so that an increase in route information is a problem.

  The above problems can be solved by dividing the roles of the current location and identifier of the IP address. For example, the network is given a value indicating the network location (hereinafter referred to as “locator”). On the other hand, the communication terminal is given an identifier value that is not controlled by the location. Then, even if the locator is changed by moving the communication terminal in communication, the identifier of the communication terminal is not changed, so that the communication is not disconnected. Further, in such a network environment, a communication terminal can use a plurality of locators as communication paths to itself. Therefore, the communication terminal can realize redundancy of the communication path by using both locators of the networks A and B. At this time, it is not necessary for the network A to propagate the locator of the network B as route information. Therefore, the problem of increasing route information is also solved.

  As a system for realizing movement of a communication terminal during communication, MIP (Mobile IP) described in Non-Patent Documents 1 and 2 is known. In MIP, an IP address assigned in a network to which a communication terminal originally belongs is called a home address and serves as a communication terminal identifier. On the other hand, an IP address assigned in the destination network is called a care-of address and is treated as a locator. Even if the care-of address is changed by moving the communication terminal through the network, the home address is not changed, so that the communication is not disconnected.

  As a method for suppressing an increase in route information, there is LISP (Locator ID Separation Protocol) described in Non-Patent Document 3. In LISP, an IP address is handled as a locator called RLOC (Routing Locator) in the Internet backbone (inter-domain space). On the other hand, in each network connected to the backbone, the IP address is handled as an identifier called EID (Endpoint ID). In LISP, EID is not restricted to RLOC. For example, a communication terminal with EID ID-1 can handle both RLOC-a and RLOC-b as its own locator. In other words, since RLOC is not restricted by EID, RLOC, which is a locator of the backbone, can be organized and managed (grouped). Accordingly, it is possible to prevent an increase in the current Internet backbone route information due to the fact that IP addresses cannot be grouped.

  As described above, a network based on an architecture that handles a communication terminal identifier (ID) and a communication terminal locator separately in communication is referred to as a “locator ID separation network”.

  By the way, in the locator ID separation network, information (referred to as “mapping information”) indicating which ID corresponds to which locator is required. The communication terminal cannot realize communication only by using the ID for the determination of the communication partner. This is because it is necessary to know the location to which the other party belongs and to determine the destination of the packet by knowing the other locator. That is, in the locator ID separation network, a transmission destination locator corresponding to the transmission destination ID is obtained, and the packet is transmitted to the transmission destination locator. The receiving side establishes a communication session by recognizing the transmission source ID in the arrived packet. On the other hand, in the return packet, the packet is transmitted toward the transmission source locator corresponding to the transmission source ID. Therefore, communication is not realized without mapping information in the locator ID separation network.

  In the locator ID separation network, there are a case where mapping end information is handled by a communication end terminal and a case where a communication relay device such as a router or a server handles the mapping information. FIG. 14 and FIG. 15 show an outline of a network based on each architecture.

  Referring to FIG. 14, since the end terminal of communication handles the mapping information 84 and 85, the end terminal performs communication by handling both the locator and the ID. The packet 101 from ID ID-1 to ID ID-2 is a packet addressed to the locator loc-b from the locator loc-a as a space for handling the locator as the locator header is encapsulated at the end terminal of ID ID-1. (In the packet header information in the figure, S-ID indicates a transmission source ID, D-ID indicates a transmission destination ID, S-loc indicates a transmission source locator, and D-loc indicates a transmission destination locator). The packet arriving at the locator loc-b is decapsulated and is found to be a packet addressed to ID ID-2. Communication from ID ID-2 to ID ID-1 (communication of packet 102) is performed in the same manner.

  On the other hand, in FIG. 15, the end terminal handles only the ID, and the relay device performs communication by adding a locator. The relay device of locator loc-a encapsulates packet 103 from ID ID-1 to ID ID-2 with reference to mapping information 86 held by itself. Since the relay device of locator loc-a has mapping information 86 with “ID ID-2 is locator loc-b”, it is encapsulated from locator loc-a to locator loc-b between the relay devices. Packet 101 is passed. The packet 101 that arrives at the relay device of the locator loc-b is decapsulated, and the packet 104 is delivered to ID ID-2. That is, in FIG. 15, the end terminal handles only the ID, and the relay apparatus handles both the locator and the ID. The aforementioned LISP employs the latter architecture.

  Hereinafter, unless otherwise specified, in this specification, as illustrated in FIG. 15, a description will be given assuming a network architecture in which a relay device handles a locator and an ID, and an end terminal handles only an ID. Also, unless otherwise specified, the relay device manages the mapping information. That is, a relay device such as a router or a server derives a locator corresponding to the ID and adds the value to the packet.

  In the above architecture, an asymmetric communication path may be used in communication between specific ID terminals (end terminals). An example of an asymmetric communication path is shown in FIG. FIG. 16 shows communication between end terminals of ID ID-1 and ID ID-2, and packets from ID ID-1 to ID ID-2 are transmitted from the relay device of locator loc-a. , ID ID-1 is assumed to be determined in the network policy on the end terminal side. Furthermore, it is assumed that the network on the end terminal side of ID ID-1 has a policy that uses the relay device of locator loc-d, which is another entrance / exit, to receive a packet to ID ID-1. Therefore, the mapping information indicating that “the packet addressed to ID ID-1 preferentially uses locator loc-d as the transmission destination” is propagated to the network backbone. Therefore, the relay device of the locator loc-b on the ID ID-2 side that receives the mapping information from the ID ID-1 side is “ID ID-1 is the locator loc-a, loc-d, and the locator loc-d The mapping information 82 of “prioritize” is held (in the mapping information 82 of FIG. 16, the locator having a small assigned number has a high priority). From the above, the packet 101 from ID ID-1 to ID ID-2 passes through the locators loc-a and loc-b, while the packet 105 from ID ID-2 to ID ID-1 is located in the locator loc-b, Asymmetric communication paths 93 and 94 via loc-d are formed.

  In a network in which communication is performed using asymmetric mapping information that forms such an asymmetric communication path, when an end terminal moves through the network, difficulty arises in efficiently optimizing the communication path. Communication optimization means eliminating redundant communication paths. The redundant communication path is generated because the mapping information between the locator and ID on the terminal side communicating with the mobile end terminal is different from the mapping information after the end terminal moves. First, redundant paths and inefficient communication path optimization will be described.

  FIG. 17 shows a redundant communication path due to movement of the end terminal. On the other hand, FIG. 18 shows a communication path optimized by communication optimization.

  In FIG. 17, it is assumed that the end terminal of ID ID-2 has moved from the network of the relay device of locator loc-b to the network of the relay device of locator loc-c. At this time, when communication optimization is not performed, the relay device of locator loc-b has mapping information 89 in which “ID ID-2 is locator loc-c” is added to its own mapping information (or ("ID ID-2 is locator local" is changed to "ID ID-2 is locator loc-c"). Therefore, the mapping information 87 of the relay device of the locator loc-a is not changed, and the packet from ID ID-1 to ID ID-2 after the movement of ID ID-2 is performed in the locators loc-a, loc-b, The broken line 95 passes through loc-c. At this time, since the route 95 via the locator loc-b is formed instead of the direct route from the locator loc-a to the locator loc-c, it becomes a redundant route (the packet of the locator loc-b relay device And then encapsulated and delivered to the locator loc-c from the mapping information of the relay device of the locator loc-b). On the other hand, since the relay device of locator loc-c knows mapping information 83 "ID ID-1 is locator loc-a, loc-d, and locator loc-d has priority", ID ID- A packet from 2 to ID ID-1 can be communicated through a path 92 via locators loc-c and loc-d.

  In general, in a field such as MIP, such a redundant communication path is called triangular routing. In order to eliminate the triangular routing, there is a method in which the relay device of locator loc-b or loc-c that knows the movement of ID ID-2 notifies the change of mapping to the relay device of the network on ID ID-1 side. Eliminating redundant routes by notifying a change in mapping is generally referred to as “communication route optimization”.

  FIG. 18 shows a case where the end terminal with ID ID-2 moves in the same network as FIG. In FIG. 18, in order to optimize communication for ID ID-1 communicating with ID ID-2, the relay device of locator loc-b has a locator loc-a corresponding to ID ID-1. “ID ID-2 is locator loc-c”, which is mapping change information, is notified to the relay device of loc-d (solid lines 402 and 403 in FIG. 18). Here, the mapping information 82 and 83 with “ID ID-1 is locator loc-a, loc-d” possessed by the relay devices of the locators loc-b and loc-c is used as the notification destination information of the mapping change. . The relay devices of the locators loc-a and loc-d that have received the mapping change notifications 402 and 403 change their mapping information to mapping information 81 and 810, respectively. Then, an optimized path 91 that does not pass through the locator loc-b as shown by the broken line in FIG. 18 is realized.

  Patent Document 1 describes a packet communication method using a node identifier and a position indicator.

JP 2008-31191 A

“IP Mobility Support for IPv4”, IETF RFC3344 (Aug 2002) “Mobility Support in IPv6”, IETF RFC3775 (Jun 2004) “Locator / ID Separation Protocol (LISP)”, IETF Internet Draft, draft-farinacci-lisp-12 (Mar 2009) “Application Mobility with HIP”, In Proc. Of NDSS Wireless and Security Workshop, San Diego, CA, USA, Feb. 2005. Internet Society.

  In FIG. 18, the mapping change is notified to all the transmission destination locators of the target ID existing in the mapping information. Therefore, as the number of locators included in the ID increases, the method of notifying all target locators becomes non-scalable and inefficient. Therefore, in order to efficiently optimize the communication path, a locator suitable for the mapping change notification is selected from the transmission destination locators corresponding to the ID to be optimized for the communication path, and the locator is notified. It is preferable.

  However, according to the conventional mapping change notification method using mapping information, it is difficult to efficiently optimize the communication path. An example in which optimization of communication becomes difficult is shown in FIG. In FIG. 19, in order to eliminate a redundant route via locator loc-b in communication from ID ID-1 to ID ID-2, the relay devices of locators loc-b and loc-c try to optimize communication. . Here, the relay devices of locators loc-b and loc-c hold mapping information 82 and 83 that “ID ID-1 is locator loc-a and loc-d, and priority is given to locator loc-d”. is doing. Therefore, in order to optimize the communication path efficiently, for example, the mapping change notification destination is reduced to one, and the mapping change is notified 404 only to the relay device of the locator loc-d having a high priority.

  However, in the ID ID-1 side network, the packet exit from ID ID-1 to ID ID-2 is used as the relay device for locator loc-a, and the mapping information of the relay device for locator loc-a is a mapping change. Since the notification 404 is not updated, the packet from ID ID-1 to ID ID-2 is still delivered to the relay device of the locator loc-b (broken line 96 in FIG. 19). When the relay device of the locator loc-b has mapping information addressed to a new ID ID-2, it becomes triangular routing. Otherwise, the packet is discarded. In FIG. 19, since the relay device of locator loc-b does not hold new mapping information addressed to ID ID-2, the packet is discarded. In any case, it is difficult to efficiently optimize the communication path. Therefore, in order to efficiently optimize the communication path, the mapping change cannot be notified to an appropriate relay device only by using the mapping information as in the past.

  Here, the structure of a general message used for notification of mapping change (“mapping change notification message”) will be described with reference to FIG. The mapping change notification message 4A includes at least a transmission destination locator (D-loc) 41 and a transmission source locator (S-loc) 42 indicating a transmission destination and a transmission source of the message, and further includes a mapping change as information indicating a change in mapping. The locator group 44 corresponding to the ID 43 and the ID to be changed is included. The relay apparatus of D-loc 41 that has received the mapping change notification message 4A converts the locator information corresponding to the mapping change ID 43 in the mapping information of itself into the locator information indicated in the locator group 44 included in the mapping change notification message 4A. change. At this time, whether or not to delete the old locator information may differ depending on the protocol followed by the relay device and the characteristics of the relay device. The mapping change notification message 4A may include a plurality of sets of locator groups 44 corresponding to the mapping change ID 43.

  By the way, the example mentioned above is an example of the network change by assuming the end terminal as a mobile node and physically moving the end terminal ID ID-2. On the other hand, in the locator ID separation network, a network change due to movement of ID is also conceivable. By moving IDs to terminals on different networks, process migration and application mobility across networks can be performed. Non-Patent Document 4 describes a method for performing ID movement over a network using an HIP (Host Identity Protocol) network, which is an architecture for realizing a locator ID separation network, for application mobility over a network. Since HIP is basically an architecture in which end terminals have a correspondence between locators and IDs, Non-Patent Document 3 is different from the network assumed in this specification. However, even in the network assumed in this specification, it is possible to move only the ID for process migration, and in the optimization of the communication path at that time, it is the same as when the end terminal physically moves Problems arise.

  In the conventional locator ID separation network, there is a problem that an appropriate notification destination of the mapping change between the locator and the ID caused by the movement of the end terminal or ID is not known. For example, there is a possibility that the relay device that notifies the mapping change may notify the inappropriate transmission destination relay device of the mapping change by determining the mapping change notification destination from its own mapping information. Also, in the network on the relay device side that receives the mapping change notification, when there are multiple relay devices that can accept the mapping change, it is impossible to control which relay device wants to be notified of the mapping change. . That is, since the mapping is not changed in an appropriate relay device, for example, an increase in communication delay or a decrease in communication band due to communication via a redundant route may occur, and in some cases, a communication session may be disconnected. In particular, a problem arises in optimizing the communication path when moving to a network with a different end terminal or ID.

  Therefore, in a locator ID separation network that handles locators and IDs separately, it becomes an issue to efficiently optimize communication paths when end terminals or IDs are moved. The objective of this invention is providing the communication system, the mapping information notification apparatus, the mapping information notification method, and program which solve this subject.

The mapping information notification device according to the first aspect of the present invention is:
Holding a correspondence table associating a pair of a transmission source ID and a transmission destination ID of a packet with a transmission source locator of the packet;
When the mapping information between the transmission destination ID and the transmission destination locator is changed, the transmission source locator associated with the transmission destination ID is extracted with reference to the correspondence table and included in the transmission source locator. The changed contents of the mapping information are notified to the packet relay apparatus.

  A communication system according to a second aspect of the present invention includes the packet relay device according to the first aspect.

The mapping information notification device according to the third aspect of the present invention is:
A step of storing a correspondence table associating a pair of a transmission source ID and a transmission destination ID of a packet with a transmission source locator of the packet in a storage device;
When mapping information between a transmission destination ID and a transmission destination locator is changed, referring to the correspondence table, extracting a transmission source locator associated with the transmission destination ID;
And a step of notifying the packet relay device included in the extracted transmission source locator of the change contents of the mapping information.

The program according to the fourth aspect of the present invention is:
A process of holding a correspondence table associating a pair of a packet transmission source ID and a transmission destination ID with a transmission source locator of the packet in a storage device;
When mapping information between a transmission destination ID and a transmission destination locator is changed, a process of extracting a transmission source locator associated with the transmission destination ID with reference to the correspondence table;
The computer is caused to execute a process of notifying the packet relay device included in the extracted transmission source locator of the change contents of the mapping information.

  According to the communication system, mapping information notification device, mapping information communication method, and program according to the present invention, in the locator ID separation network that handles the locator and the ID separately, the communication path is optimized when the end terminal or the ID is moved. It can be done efficiently.

It is a block diagram which shows the structure of the corresponding table production | generation apparatus in the communication system which concerns on the 1st Embodiment of this invention as an example. It is a figure which shows the structure of the transmission source locator correspondence table in the communication system which concerns on the 1st Embodiment of this invention as an example. It is a flowchart which shows operation | movement of the corresponding table production | generation apparatus in the communication system which concerns on the 1st Embodiment of this invention as an example. It is a block diagram which shows as an example the structure of the corresponding | compatible table holding | maintenance apparatus in the communication system which concerns on the 1st Embodiment of this invention. It is a flowchart which shows operation | movement of the correspondence table holding | maintenance apparatus in the communication system which concerns on the 1st Embodiment of this invention as an example. It is a block diagram which shows the structure of the mapping change notification apparatus in the communication system which concerns on the 1st Embodiment of this invention as an example. It is a flowchart which shows operation | movement of the mapping change notification apparatus in the communication system which concerns on the 1st Embodiment of this invention as an example. It is a figure which shows the message format of the corresponding | compatible information message in the communication system which concerns on the 1st Embodiment of this invention as an example. It is a figure for demonstrating the packet communication in the communication system which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the structure of the corresponding | compatible table holding | maintenance apparatus in the communication system which concerns on the 2nd Embodiment of this invention as an example. It is a flowchart which shows the operation | movement regarding registration of the correspondence table information of the correspondence table holding | maintenance apparatus in the communication system which concerns on the 2nd Embodiment of this invention, and a reference response as an example. It is a flowchart which shows the operation | movement regarding the dispersion | distribution arrangement | positioning process of the corresponding table of the corresponding table holding | maintenance apparatus 2B and 2B 'in the communication system which concerns on the 2nd Embodiment of this invention as an example. It is a figure for demonstrating the packet communication in the communication system which concerns on the 3rd Embodiment of this invention. It is a figure which shows the conventional locator ID isolation | separation network which an end terminal hold | maintains the correspondence (mapping) of a locator and ID as an example. It is a figure which shows the conventional locator ID isolation | separation network which a relay apparatus hold | maintains the correspondence (mapping) of a locator and ID as an example. It is a figure which shows the conventional locator ID isolation | separation network containing an asymmetrical communication path as an example. It is a figure which shows as an example the triangular routing which arises by the movement of an end terminal or ID in the conventional locator ID isolation | separation network which has symmetrical mapping information. It is a figure which shows the optimization of the communication path in the conventional locator ID isolation | separation network which has symmetrical mapping information as an example. It is a figure which shows as an example the situation where it is difficult to optimize a communication path in the conventional locator ID separation network having asymmetric mapping information. It is a figure which shows the conventional typical message format which notifies mapping change as an example.

  The mapping information notification device according to the first development form is preferably the mapping information notification device according to the first viewpoint.

  The mapping information notification device according to the second development form may hold the correspondence table in a distributed manner with other mapping information notification devices.

  When the mapping information between the transmission destination ID and the transmission destination locator is changed, the mapping information notification apparatus according to the third development form displays the correspondence table distributed and held among the plurality of mapping information notification apparatuses. The transmission source locator associated with the transmission destination ID may be extracted with reference to the packet relay device included in the transmission source locator, and the change contents of the mapping information may be notified.

  The mapping information notification device according to the fourth development form may relay a packet.

  The communication system according to the fifth development form preferably includes the above-described mapping information notification device.

  The communication system according to the sixth embodiment generates a correspondence table that associates a pair of a transmission source ID and a transmission destination ID of a packet with a transmission source locator of the packet, and transmits the correspondence table to the mapping information notification device. It is preferable to further include a table generation device.

  In the communication system according to a seventh development form, the correspondence table generation device may relay a packet.

  The mapping information notification method according to the eighth development form is preferably the mapping information notification method according to the third aspect.

  The mapping information notification method according to the ninth development mode may further include a step in which the computer distributes and holds the correspondence table with other computers.

In the mapping information notifying method of the tenth development mode, when the mapping information between the transmission destination ID and the transmission destination locator is changed, the correspondence table held in a distributed manner among a plurality of computers is used. A step of referring to and extracting a transmission source locator associated with the transmission destination ID;
And a step of notifying the packet relay device included in the extracted transmission source locator of the change contents of the mapping information.

  The mapping information notifying method according to the eleventh development mode may further include a step in which the computer relays the packet.

In a mapping information notification method according to a twelfth development mode, a computer generates a correspondence table that associates a set of a transmission source ID and a transmission destination ID of a packet with a transmission source locator of the packet;
It is preferable that the method further includes a step of transmitting the correspondence table to another computer.

  The program according to the thirteenth development form is preferably a program according to the fourth viewpoint.

  The program according to the fourteenth expansion form may further cause the computer to execute processing for distributing and holding the correspondence table with other computers.

When the mapping information between the transmission destination ID and the transmission destination locator is changed, the program of the fifteenth development mode refers to the transmission destination by referring to the correspondence table distributed and held among a plurality of computers. A process of extracting a transmission source locator associated with the ID;
You may make it make a computer perform further the process which notifies the change content of the said mapping information to the packet relay apparatus contained in the extracted transmission origin locator.

  The program according to the sixteenth expansion form may further cause the computer to execute a process of relaying the packet.

The program of the seventeenth development form generates a correspondence table that associates a set of a transmission source ID and a transmission destination ID of a packet with a transmission source locator of the packet;
It is preferable to further cause the computer to execute processing for transmitting the correspondence table to another computer.

  According to the communication system, mapping information notification device, mapping information communication method, and program according to the present invention, in the locator ID separation network that handles the locator and the ID separately, the communication path is optimized when the end terminal or the ID is moved. It can be done efficiently. By using a correspondence table that associates a pair of a packet transmission source ID and a transmission destination ID with a transmission source locator of the packet, only for the packet relay device that needs to notify that the mapping information has been changed. This is because notification can be made.

(First embodiment)
A communication system according to a first embodiment of the present invention will be described in detail with reference to the drawings. In the first embodiment, the configuration and processing operation of a correspondence table generating device such as a router or a server that generates a correspondence table of a transmission source locator corresponding to a transmission destination ID, and the configuration and processing of a correspondence table holding device that holds the correspondence table Operation, configuration and processing operation of a mapping change notification device such as a router or server that performs mapping change notification, mapping change notification and communication path optimization by a correspondence table generation device and mapping change notification device will be described. The function of the correspondence table generation device according to the present invention may be incorporated in a relay device such as a router or a server, or may be realized by a new device such as a server for the present invention different from that.

  Note that the present invention relates to a network composed of an architecture and a protocol for realizing a general locator ID separation network. The following description assumes a network in which a relay device such as a router or server manages and controls mapping information indicating the correspondence between a locator and an ID. However, the present invention can also be applied to a network in which end terminals manage and control mapping information indicating correspondence between locators and IDs. For example, when the end terminal has the function of a relay device, the present invention can be provided. Therefore, the present invention is not limited to a network in which a relay device manages and controls mapping information.

  In the communication system according to the first embodiment, for each ID of a transmission destination terminal that communicates with an end terminal of its own network, the correspondence table generation apparatus has a locator (transmission source locator) of a relay apparatus serving as an exit of the packet. A correspondence table is generated, the correspondence table holding device holds the correspondence table, and receives a reference to the correspondence table, thereby informing the mapping change notification device of an appropriate mapping notification destination locator. The mapping change notification device can notify the mapping change to the relay device of an appropriate locator obtained from the correspondence table. Here, the mapping change indicates that at least one of addition and deletion of mapping information is performed in addition to the addition and deletion of mapping information.

  First, an apparatus (corresponding table generating apparatus) that generates a correspondence table of transmission source locators corresponding to transmission destination IDs will be described with reference to FIG. FIG. 1 is a block diagram illustrating an example of the configuration of the correspondence table generation device 1A in the communication system according to the present embodiment. In the apparatus of FIG. 1, elements related to each component are connected by a straight line and displayed. The direction of the arrow line indicates the detailed control and reference between components and the flow of information for explaining the feature of the present invention.

  The correspondence table generation device 1A generates a correspondence table of a transmission source locator corresponding to a transmission destination ID based on information of a network to which the device belongs and a communication policy used between the networks, and stores the correspondence table in a database. .

  The correspondence table generation device 1 </ b> A includes a correspondence table management unit 11, a policy management unit 12, and an external connection interface 13. In addition, a transmission source locator correspondence table DB6 is provided outside. Hereinafter, the configuration and operation of the correspondence table generation device 1A will be described.

  The correspondence table management unit 11 includes at least a correspondence table generation unit 111 and a correspondence table registration unit 112. The correspondence table management unit 11 generates a correspondence table of the transmission source locator corresponding to the transmission destination ID with reference to the policy information received from the policy management unit 12, and stores the correspondence table in the transmission source locator correspondence table DB6. The correspondence table generation unit 111 receives policy information from the policy management unit 12, determines which transmission source locator is used for which transmission destination ID, that is, what is the transmission source locator for the transmission destination ID, and transmits A correspondence table of transmission source locators for the destination ID is generated. The correspondence table registration unit 112 stores the correspondence table by registering the correspondence table generated by the correspondence table generation unit 111 in the transmission source locator correspondence table DB 6.

  The policy management unit 12 includes a policy reception unit 121 and a policy storage unit 122. The policy receiving unit 121 receives policy information from the outside via the external connection interface 13 and arranges necessary information. The policy storage unit 122 receives and stores the policy information arranged from the policy reception unit 121, and provides the policy information to the correspondence table generation unit 111 of the correspondence table management unit 11 as necessary. Here, the policy refers to information about which transmission source locator is used for which transmission destination ID (priority information of the transmission source locator), information on transmission destination locators and transmission source locators that cannot be used in the ID, and the like. Refers to the operation method.

  The external connection interface 13 is an interface for exchanging information with an external terminal.

  In the above correspondence table generating device 1A, a correspondence table generating device 1A '(not shown) having the transmission source locator correspondence table DB6 inside the device 1A is also conceivable. The configuration and operation of the correspondence table generation device 1A 'are the same as those of the correspondence table generation device 1A, except that the transmission source locator correspondence table DB6 is provided therein.

  Next, the configuration of the transmission source locator correspondence table 5A in the communication system according to the present embodiment will be described with reference to FIG. FIG. 2 is an example of the transmission source locator correspondence table 5A according to the present embodiment. The transmission source locator correspondence table 5A is stored in the transmission source locator correspondence table DB6.

  The transmission source locator correspondence table 5A includes transmission source ID, transmission destination ID, and transmission source locator information. The transmission source locator correspondence table 5A indicates that the relay device of the transmission source locator is used as the communication exit of the transmission source side network in the communication from the transmission source ID to the transmission destination ID. In other words, in communication from the transmission source ID to the transmission destination ID, communication using the transmission source locator as an exit is performed.

  Next, the operation of the correspondence table generating apparatus 1A (or 1A ') according to the present invention will be described with reference to FIG. FIG. 3 is an example of a flowchart showing a part of the operation of the correspondence table generating apparatuses 1A and 1A 'according to the present invention.

  When a correspondence table generation request is generated (Yes in step S10), the correspondence table generating device 1A (or 1A ') generates a correspondence table (step S11). If there is no request (No in step S10), it is determined whether or not there is a correspondence table registration request (step S12).

  If there is a correspondence table generation request (Yes in step S10), the correspondence table generation unit 111 of the correspondence table management unit 11 refers to the policy information received from the policy storage unit 122 of the policy management unit 12, and the transmission source locator A correspondence table 5A is generated (step S11).

  When the correspondence table registration request is generated (Yes in step S12), the correspondence table generating device 1A (or 1A ') registers the transmission source locator correspondence table 5A (step S13). If there is no request (No in step S12), it is determined whether or not the process termination condition is satisfied (step S14).

  When there is a correspondence table registration request (Yes in step S12), the correspondence table registration unit 112 registers the information of the transmission source locator correspondence table 5A in the transmission source locator correspondence table DB 6 (step S13), and ends the process.

  It is determined whether or not an end condition of the process is satisfied (step S14). If not satisfied (No in step S14), the process proceeds to step S10, and if satisfied (Yes in step S14), the process ends. To do.

  In the above processing operation, the correspondence table generation request and the correspondence table registration request may be generated inside the correspondence table generation device 1A (or 1A ′) or may be given from an external device. . For example, a request may be generated from a router or server that is an external device at the time of initial communication with the transmission destination ID or at the time of acquiring mapping information of the transmission destination ID. In addition, the processing termination condition in step S14 can be arbitrarily set in the operation of the correspondence table generation device 1A (or 1A '). For example, there may be a condition that the process is terminated only when there is no correspondence table generation request and a correspondence table registration request, or a condition that the process is terminated even when one of the requests is not present.

  Next, a correspondence table holding device that holds the correspondence table generated by the correspondence table generation device 1A according to the present invention will be described with reference to FIG. FIG. 4 is a block diagram illustrating an example of the configuration of the correspondence table holding device 2A in the communication system according to the present embodiment. In the apparatus of FIG. 4, elements related to each component are connected by a straight line and displayed. The direction of the arrow line indicates the detailed control and reference between components and the flow of information for explaining the feature of the present invention.

  The correspondence table holding device 2A receives information on the correspondence table generated by an external device such as the correspondence table generation device 1A, registers the information in the database, and responds to a reference request from a mapping change notification device, which will be described later, a database correspondence table. Reply with information. That is, in the correspondence table generation device 1A, the correspondence table registration unit 112 of the correspondence table management unit 11 does not directly register the correspondence table information in the transmission source locator correspondence table DB 6 but handles the correspondence table via the correspondence table holding device 2A. A form of registering table information is conceivable. In this case, the function of the correspondence table generating device 1A is changed so that a message including correspondence table information is transmitted from the correspondence table registration unit 112 of the correspondence table management unit 11 via the external connection interface 13.

  The correspondence table holding device 2A includes a correspondence table DB change processing unit 21, a correspondence table information transmitting / receiving unit 22, and an external connection interface 23. In addition, a transmission source locator correspondence table DB6 is provided outside. Hereinafter, the configuration and operation of the correspondence table holding device 2A will be described. Further, the configuration of the correspondence table is in accordance with the transmission source locator correspondence table 5A, and the correspondence table information indicates all or part of the information constituting the transmission source locator correspondence table 5A.

  The correspondence table DB change processing unit 21 includes a correspondence table DB change unit 211 and a correspondence table DB reference unit 212. The correspondence table DB change processing unit 21 receives correspondence table information from the outside and registers it in the database. It also accepts external reference to correspondence table information and returns correspondence table information held in the database. The correspondence table DB changing unit 211 receives the correspondence table information from the correspondence table information receiving unit 221 of the correspondence table information transmitting / receiving unit 22 and changes the correspondence table of the transmission source locator correspondence table DB6. The correspondence table DB reference unit 212 receives an external correspondence table reference request, and obtains corresponding correspondence table information from the transmission source locator correspondence table DB6. After obtaining, the correspondence table information transmitting unit 222 is instructed to return the obtained correspondence table information.

  The correspondence table information transmission / reception unit 22 includes a correspondence table information reception unit 221 and a correspondence table information transmission unit 222. The correspondence table information transmission / reception unit 22 performs transmission / reception processing of correspondence table information. The correspondence table information receiving unit 221 receives correspondence table information from the outside, converts it into a format handled by the correspondence table holding device 2A, and passes it to the correspondence table DB changing unit 211. The correspondence table information transmission unit 222 converts the correspondence table information received from the correspondence table DB reference unit 212 to an external transmission format, and performs transmission processing.

  The external connection interface 23 is an interface for exchanging information with an external terminal.

  In the above, the change of the correspondence table in the transmission source locator correspondence table DB6 indicates both operations of adding information to the correspondence table and deleting information from the correspondence table.

  In the above correspondence table holding device 2A, a correspondence table holding device 2A '(not shown) having a transmission source locator correspondence table DB6 therein can also be considered. The configuration and operation of the correspondence table holding device 2A 'are the same as those of the correspondence table holding device 2A except that the transmission source locator correspondence table DB6 is provided therein.

  Next, the operation of the correspondence table holding device 2A according to the present invention will be described with reference to FIG. FIG. 5 is an example of a flowchart showing a part of the operation of the correspondence table holding device 2A in the communication system according to the present embodiment.

  When the correspondence table holding device 2A (or 2A ') receives the correspondence table information from the external device (Yes in step S20), the received information is registered in the transmission source locator correspondence table DB 6 (step S21). In other cases (No in step S20), it is determined whether a reference request for correspondence table information has been received (step S22).

  When the correspondence table information is received (Yes in step S20), the correspondence table DB change unit 211 of the correspondence table DB change processing unit 21 changes the information in the transmission source locator correspondence table DB6 based on the received correspondence table information (step S20). S21).

  When a reference request for correspondence table information is received from an external device (Yes in step S22), information corresponding to the reference is obtained (step S23). In other cases (No in step S22), it is determined whether or not to end the process (step S25).

  When the correspondence table information reference request is received (Yes in step S22), the correspondence table DB reference unit 212 obtains the correspondence table information to be referred to from the transmission source locator correspondence table DB 6 (step S23).

  The correspondence table DB reference unit 212 passes the obtained correspondence table information to the correspondence table information transmission unit 222 of the correspondence table information transmission / reception unit 22, and the correspondence table information transmission unit 222 transmits the correspondence table information to the external device (step S24). ).

  It is determined whether or not the process termination condition is satisfied (step S25). If not satisfied (No in step S25), the process proceeds to step S20, and if satisfied (Yes in step S25), the process is performed. Exit.

  In the above process, the process end condition in step S25 can be arbitrarily set in the operation of the correspondence table generating apparatus 2A. For example, there may be a condition that the process is terminated only when both reception of correspondence table information and transmission of correspondence table information are absent, and a condition that the process is terminated even when there is no request for one of them.

  Next, an apparatus (mapping change notification apparatus) that performs mapping change notification to the relay apparatus will be described with reference to FIG. FIG. 6 is a block diagram illustrating an example of the configuration of the mapping change notification device 3A in the communication system according to the present embodiment. In the apparatus of FIG. 6, elements related to each component are connected by a straight line and displayed. The direction of the arrow line indicates the detailed control and reference between components and the flow of information for explaining the feature of the present invention.

  In the optimization of the communication path, the mapping change notification device 3A sends a mapping change notification from the transmission source locator correspondence table DB 6 provided in the correspondence table holding device 2A (or 2A ′) or the correspondence table generation device 1A (or 1A ′). A transmission destination locator, that is, a locator of the mapping change notification destination relay apparatus is obtained. And the change of mapping is notified to the relay device of the acquired locator.

  The mapping change notification device 3A includes a locator information acquisition unit 31, a mapping change notification unit 32, a packet transmission / reception unit 33, and an external connection interface 34. Hereinafter, the configuration and operation of the mapping change notification device 3A will be described.

  Referring to FIG. 6, locator information acquisition unit 31 includes a corresponding locator reference request unit 311 and a corresponding locator information acquisition unit 312. The locator information acquisition unit 31 uses the locator reference request unit 311 to locate the reference target ID (“reference target ID”) and the message transmission source ID (“reference target transmission source ID”) to the reference target ID. Information is requested from the external device, and the corresponding locator information acquisition unit 312 receives locator information (“corresponding locator information”) for the set of the reference target ID and the reference target transmission source ID from the external device.

  Here, the “reference target ID” is an ID that requires a mapping change because the locator is switched by the movement of the terminal or the ID. The “reference target transmission source ID” is an ID of a transmission source communicating with the reference target ID.

  The corresponding locator reference request unit 311 instructs the packet transmission unit 332 of the packet transmission / reception unit 33 to transmit a message requesting locator information corresponding to the set of the reference target ID and the reference target transmission source ID. The corresponding locator information acquisition unit 312 receives a message including the corresponding locator information from the packet reception unit 331, and acquires the corresponding locator information for the set of the reference target ID and the reference target transmission source ID. Then, it instructs the mapping change notification unit 32 to generate a mapping change message addressed to the corresponding locator.

  Referring to FIG. 6, the mapping change notification unit 32 includes a change notification message generation unit 321. The change notification message generation unit 321 generates a mapping change notification message from the corresponding locator information and the reference target ID information received from the corresponding locator information acquisition unit 312 of the locator information acquisition unit 31. A mapping change notification message addressed to the corresponding locator is generated, and the reference target ID is included as the mapping change target ID (“mapping change ID”). Moreover, the locator information of the movement destination of the reference target ID is included as new locator information of the mapping change ID.

  The format of the mapping change notification message follows, for example, the mapping change notification message 4A in FIG. That is, the corresponding locator is given to the transmission destination locator (D-loc) 41, the reference object ID is given to the mapping change ID 43, and the locator information of the movement destination of the reference object ID is given to the corresponding locator group 44. The source locator (S-loc) 42 basically contains the locator of the mapping change notification device 3A, but depending on the protocol of the locator ID separation network, the locator of the device to which the reference target ID is moved, etc. May contain locator information. In addition, the change notification message generation unit 321 passes the generated mapping change notification message to the packet transmission unit 332 of the packet transmission / reception unit 33.

  Referring to FIG. 6, the packet transmission / reception unit 33 includes a packet reception unit 331 and a packet transmission unit 332. The packet receiving unit 331 receives a packet via the external connection interface 34 and passes a message including the corresponding locator information to the corresponding locator information acquiring unit 312 of the locator information acquiring unit 31. The packet transmission unit 332 sends a message including a content requesting the corresponding locator corresponding to the set of the reference target ID and the reference target transmission source ID received from the corresponding locator reference request unit 311 to an external device (correspondence table). Holding device 2A, 2A 'and correspondence table generating device 1A, 1A'). Further, it receives a mapping change notification message packet from the change notification message generation unit 321 of the mapping change notification unit 32, and transmits the packet to an external relay device via the external connection interface 34.

  The external connection interface 34 is an interface for performing transmission / reception of packets with an external terminal.

  Next, the processing operation of the mapping change notification device 3A according to the present invention will be described with reference to FIG. FIG. 7 is an example of a flowchart showing a part of the operation of the mapping change notification device 3A according to the present invention.

  When the locator reference request for the reference target ID is generated (Yes in step S30), the mapping change notification device 3A transmits a reference request message for the corresponding locator (step S31). When the reference request has not occurred (No in step S30), it is determined whether or not a message including any reference target ID and the corresponding locator for the reference target transmission source ID is received (step S32).

  The corresponding locator reference request unit 311 of the locator information acquisition unit 31 generates a request message for referring to the locator for the reference target ID and the reference target transmission source ID, and instructs the packet transmission unit 332 of the packet transmission / reception unit 33 to transmit. The packet transmission unit 332 transmits the message to the external device of the correspondence table holding device 2A (or 2A ') or the correspondence table generation device 1A (or 1A') (step S31).

  When the mapping change notification device 3A receives a response message including the reference target ID for which a reference request has been issued in the past and the locator information for the reference target transmission source ID (Yes in step S32), the corresponding locator information acquisition unit 312 Message information is acquired, and a mapping change message is generated (step S33). If not received (No in step S32), it is determined whether or not the process termination condition is satisfied (step S35).

  The change notification message generation unit 321 of the mapping change notification unit 32 generates a mapping change notification message addressed to the corresponding locator included in the received message (step S33). The message is generated with at least the corresponding locator as the transmission destination locator (D-loc) 41, the reference target ID of the corresponding locator as the mapping change ID 43, and the destination locator information of the reference target ID as the corresponding locator group 44.

  In accordance with the instruction from the change notification message generation unit 321, the packet transmission unit 332 transmits the generated mapping change notification message (step S34).

  It is determined whether or not the process termination condition is satisfied (step S35). If not satisfied (No in step S35), the process proceeds to step S30, and if satisfied (Yes in step S35), the process is performed. Exit.

  In the above process, the process end condition in step S35 can be arbitrarily set in the operation of the correspondence table generating apparatus 3A. For example, a condition that the process is terminated only when there is no reception of a message including the corresponding locator information and a transmission of a reference request message, and a condition that the process is terminated even when there is no one of the transmission and reception processes.

  Next, when the correspondence table generating device 1A (or 1A ′) according to the present invention transmits the correspondence table holding device 2A (or 2A ′), the correspondence table generating device 1A (or 1A ′) or the correspondence table holding device 2A ( Or 2A ′) from the mapping change notification device 3A to the mapping table generation device 1A (or 1A ′) or the mapping table holding device 2A (or 2A ′). A configuration of the correspondence table information message 7A including correspondence table information generally used in the present invention will be described with reference to FIG. FIG. 8 shows an example of the format of the correspondence table information message 7A according to the present invention.

  The correspondence table information message 7A includes a message type 71, a transmission destination ID 72, a transmission source ID 73, and a transmission source locator group 74.

  The message type 71 identifies the message from which device to which device, whether the message is a request for correspondence table information, a response to correspondence table information, or registration of correspondence table information. Used to do. The message type contains a value for identifying these. For example, a message for registering correspondence table information is a message from the correspondence table generation device 1A (or 1A ′) to the correspondence table holding device 2A (or 2A ′) as type 1, and a message for requesting correspondence table information. A correspondence table generation device that is a message that makes a type 2 message from the mapping change notification device 3A to the correspondence table generation device 1A (or 1A ′) or the correspondence table holding device 2A (or 2A ′) and responds to correspondence table information. The type of message is identified by setting the message from 1A (or 1A ') or the correspondence table holding device 2A (or 2A') to the mapping change notification device 3A as type 3.

  The transmission destination ID 72 is a transmission destination ID of a packet from the transmission source ID 73, and indicates the transmission destination ID in the transmission source locator correspondence table 5A. The transmission source ID 73 is a transmission source ID that transmits a packet to the transmission destination ID 72, and indicates the transmission source ID in the transmission source locator correspondence table 5A. The transmission source locator group 74 is a transmission source locator used when the transmission source ID 73 performs communication with the transmission destination ID 72, that is, a set of transmission source locators. The transmission source locator correspondence table 5A indicates the transmission source locator.

  According to the identification of the message type in the above example, the type 1 message includes all information of the transmission destination ID 72, the transmission source ID 73, and the transmission source locator group 74. That is, in the network on the transmission source ID side, a message for registering which transmission source locator group 74 is used in communication from the transmission source ID 73 to the transmission destination ID 72 is used.

  The type 2 message includes at least information on the transmission destination ID 72 and the transmission source ID 73. The destination ID 72 contains the value of the aforementioned reference object ID, and the sender ID 73 contains the aforementioned reference object sender ID. That is, the message requests a transmission source locator of a reference target transmission source ID that is communicating with a reference target ID whose mapping needs to be changed.

  The type 3 message includes all information of the transmission destination ID 72, the transmission source ID 73, and the transmission source locator group 74. As with Type 2, the destination ID 72 contains the value of the aforementioned reference object ID, and the sender ID 73 contains the aforementioned reference object sender ID. The difference is that the value of the transmission source locator in the communication from the reference target transmission source ID to the reference target ID is included in the transmission source locator group 74. That is, it is a message that responds as to which transmission source locator is used in communication from the reference target transmission source ID to the reference target ID.

  Next, referring to FIG. 9, the correspondence table holding device 2A (or 2A ') and registration table registration by the correspondence table information generating device 1A (or 1A') and the correspondence table holding device 2A (or 2A ') Regarding the request and response of the correspondence table by the mapping change notification device 3A, communication path optimization by the mapping change notification device 3A will be described. In FIG. 9, it is assumed that the relay device of locator loc-a has the function of correspondence table information generation device 1A, and the relay device of locator loc-b has the function of mapping change notification device 3A. Further, although the correspondence table holding device 2A is used as the correspondence table holding device, the correspondence table holding device may be the correspondence table holding device 2A ′.

  Since the relay device 1A of the locator loc-a uses the locator loc-a as the transmission source locator of the packet addressed from ID ID-1 to ID ID-2 based on the policy of its own network, the registration identifier is assigned to the message type 71. Then, a correspondence table information message 701 in which the transmission destination ID 72 is ID ID-2, the transmission source ID 73 is ID ID-1, and the transmission source locator group 74 is locator loc-a is transmitted to the correspondence table information device 2A.

  Upon receiving the registration type correspondence table message 701, the correspondence table information device 2A changes the transmission source locator correspondence table DB6 from the received information.

  The relay device 3A of the locator loc-b moves the ID ID-2 terminal from its own network to the network of the locator loc-c, so that the ID ID-2 mapping information is “ID ID-2 is the locator loc-b. ”To“ ID ID-2 is changed to locator loc-c ”. Here, the relay device of locator loc-b is informed of the movement of ID ID-2 by the relay device of locator loc-c, and changes the mapping information to the locator loc of the network before the movement of ID ID-2. Sharing between the relay device of -b and the relay device of the locator loc-c after movement is conceivable. At this time, the relay device of locator loc-b determines the destination of the mapping change notification message in order to optimize the communication path with the terminal with ID ID-1 that is communicating with the terminal with ID ID-2. Investigate. In order to check the transmission destination of the mapping change notification message, the relay device of the locator loc-b gives a request identifier to the message type, sets the transmission destination ID 72 as ID ID-2, and sets the transmission source ID 73 as ID ID-1. A table information message 702 is transmitted to the correspondence table information apparatus 2A.

  The correspondence table information device 2A that has received the request type correspondence table information message 702 from the relay device of the locator loc-b has the transmission source ID of ID ID-1 and the transmission destination ID of the transmission source locator correspondence table DB6. A locator loc-a which is a transmission source locator in the case of ID ID-2 is obtained. Then, a response identifier is given to the message type, a correspondence table information message 703 with a destination ID 72 of ID ID-2, a source ID 73 of ID ID-1, and a source locator group 74 of locator loc-a is assigned to a locator loc- b to the relay device.

  The mapping change notification device 3A that has obtained the transmission destination of the mapping change notification message from the correspondence table information device 2A uses the transmission destination locator (D-loc) 41 as the transmission source locator loc-loc, and the transmission source locator (S- loc) 42 is the locator loc-b that is its locator, the mapping change ID 43 is the ID ID-2 of the terminal that moved, and the corresponding locator 44 is the locator loc-c that is the locator to which the ID is moved A notification message 401 is generated and transmitted to the relay device of locator loc-a.

  Upon receiving the mapping change notification message 401, the relay device of locator loc-a changes the mapping information of ID ID-2 from “ID ID-2 is locator loc-b” to “ID ID-2 is locator loc-c”. Thereafter, the transmission destination locator for packets addressed from ID ID-1 to ID ID-2 is transmitted as locator loc-c. At this time, communication is performed through a communication path such as a line 91 in the drawing. On the other hand, a packet addressed from ID ID-2 to ID ID-1 is performed on the communication path of line 92 in the figure.

  As described above, a relay device such as a router or server, or a device such as a server for the present invention generates a correspondence table of transmission source locators for transmission source IDs and transmission destination IDs, and holds the correspondence table. When the locator information corresponding to the movement ID is changed due to the movement of the end terminal or ID, the notification of the appropriate mapping change is notified from the held correspondence table when the mapping change is notified in order to optimize the communication. You can know the source locator ahead. Therefore, the relay device that performs the mapping change notification can transmit the mapping change notification message to an appropriate relay device in communication optimization.

  According to the communication system of this embodiment, in the locator ID separation network, optimization of communication paths accompanying movement of end terminals and IDs can be performed in a scalable and efficient manner. Further, the mapping change notification message can be transmitted to the desired transmission source locator in the network on the correspondence table generation side. Therefore, when an end terminal or ID in the locator ID separation network moves, the communication delay is reduced and the broadband communication band is secured while considering the policy of the network that receives the mapping change notification. Can be used effectively) and the connection of the communication session can be continued.

(Second Embodiment)
A communication system according to a second embodiment of the present invention will be described with reference to the drawings. In the communication system according to the second embodiment, there are a plurality of correspondence table holding devices that hold correspondence tables, and the correspondence tables are distributed and held among the correspondence table holding devices. That is, in the communication system of the present embodiment, a plurality of correspondence table holding devices distribute and hold the correspondence table generated by the correspondence table generating device that generates the correspondence table. Hereinafter, the configuration and operation of the correspondence table holding device will be described.

  First, a correspondence table holding device that holds a correspondence table generated by the correspondence table generation device 1A according to the present invention will be described with reference to FIG. FIG. 10 is a block diagram illustrating an example of the configuration of the correspondence table holding device 2B in the communication system according to the present embodiment. In the apparatus shown in FIG. 10, the elements related to each component are connected by a straight line and displayed. The direction of the arrow line indicates the detailed control and reference between components and the flow of information for explaining the feature of the present invention.

  The correspondence table holding device 2B receives correspondence table information generated by an external device such as the correspondence table generation device 1A, distributes the information among the correspondence table holding devices 2B, registers them in the database, and receives a mapping change notification device described later. In response to the reference request, the correspondence table information of the database is searched between the correspondence table holding devices and responds. The correspondence table holding device 2B includes a correspondence table DB configuration processing unit 24 in addition to the configuration of the correspondence table holding device 2A. In addition, addition and change of functions are added to each part of the correspondence table holding device 2A. Hereinafter, the configuration and operation of the correspondence table holding device 2B will be described.

  The correspondence table DB change processing unit 21 includes a correspondence table DB change unit 211 and a correspondence table DB search unit 213 instead of the correspondence table reference unit 212 in the correspondence table holding device 2A. The correspondence table DB change processing unit 21 receives correspondence table information from the outside and registers it in the database. It also accepts external reference to correspondence table information, searches for correspondence table information held in the database, and returns it. The correspondence table DB changing unit 211 is basically the same as the function of the correspondence table holding device 2A. The correspondence table DB search unit 213 responds to a request for reference to a correspondence table from an external device such as a mapping change notification device, referring to the database configuration information from the correspondence table DB configuration processing unit 24, and the transmission source managed by itself The database including the locator correspondence table DB6 is searched for the requested information, and the finally obtained correspondence table information is transmitted to the external device.

  The correspondence table DB configuration processing unit 24 includes a correspondence table DB configuration calculation unit 241 and a correspondence table DB policy management unit 242. The correspondence table DB configuration processing unit 24 distributes and holds correspondence table information in a plurality of databases in accordance with operation and configuration policies (configuration method, etc.). The correspondence table DB configuration calculation unit 241 calculates how the correspondence table information is actually held among a plurality of databases according to the operation and configuration policy such as the configuration method given by the correspondence table DB policy management unit 242. . Also, the calculated result is notified to the correspondence table DB change unit 211 of the correspondence table DB change processing unit 21, the information of the transmission source locator correspondence table DB6 managed by the own correspondence table holding device 2B is changed, and another correspondence is newly created. The correspondence table information related to the change is transmitted so that the correspondence table information related to the change is retained in the transmission source locator correspondence table DB 6 of the table holding device 2B. The correspondence table DB policy management unit 242 manages the operation such as the configuration method and the configuration policy, and passes policy information to the correspondence table DB configuration calculation unit 241 as necessary. The policy information may be given from the outside, or the policy held and managed by the correspondence table DB policy management unit 242 may be changed according to an instruction from the operator.

  In the above correspondence table holding device 2B, a correspondence table holding device 2B '(not shown) having a transmission source locator correspondence table DB6 therein is also conceivable. The configuration and operation of the correspondence table holding device 2B 'are the same as those of the correspondence table holding device 2B, except that the transmission source locator correspondence table DB6 is provided therein.

  Next, the operation of the correspondence table holding device 2B '(or 2B') according to the present invention will be described with reference to FIGS. 11 and 12 are examples of flowcharts showing a part of the operation of the correspondence table holding device 2B (or 2B ') according to the present invention, and basically operate in parallel.

  First, FIG. 11 will be described. FIG. 11 shows a correspondence table information registration processing method and correspondence table information search processing method of the correspondence table holding device 2B (or 2B ').

  When the correspondence table holding device 2B (or 2B ') receives correspondence table information from the external device (Yes in step S40), the received information is registered in the transmission source locator correspondence table DB 6 (step S41). In other cases (No in step S40), it is determined whether a reference request for correspondence table information has been received (step S42).

  When the correspondence table information is received (Yes in step S40), the correspondence table DB change unit 211 of the correspondence table DB change processing unit 21 changes the information in the transmission source locator correspondence table DB 6 based on the received correspondence table information ( Step S41).

  When a reference request for correspondence table information is received from an external device (Yes in step S42), information corresponding to the reference is obtained (step S43). In other cases (No in step S42), it is determined whether or not to end the process (step S47).

  When a reference request for correspondence table information is received (Yes in step S42), from the database configuration information calculated by the correspondence table DB configuration calculation unit 241 of the correspondence table DB configuration processing unit 24 and the information of the transmission source locator correspondence table DB6 Then, an access destination for obtaining the requested information is obtained (step S43). The access destination is the correspondence table holding device 2B (or 2B '), 2A (or 2A'), the correspondence table generating device 1A (or 1A '), or the transmission source locator correspondence table DB6.

  When the access destination for obtaining the requested information is the transmission source locator correspondence table DB6 managed by the correspondence table DB search unit 213 (Yes in step S44), the correspondence table DB search unit 213 obtains the information (step S45). ). If the access destination is another device (No in step S44), a new correspondence table reference request is transmitted (step S46).

  The correspondence table DB search unit 213 obtains information requested for reference from the transmission source locator correspondence table DB 6 managed by itself, and passes the obtained correspondence table information to the correspondence table information transmission unit 222 of the correspondence table information transmission / reception unit 22. The correspondence table information transmission unit 222 transmits the correspondence table information to the external device (step S45).

  The correspondence table DB search unit 213 generates a reference request message for correspondence table information (for example, a correspondence table information message of the request type) in order to transmit a reference request to another device again, and sends it to the access destination device. The generated message is transmitted (step S46).

  It is determined whether or not the process termination condition is satisfied (step S47). If not satisfied (No in step S47), the process proceeds to step S40, and if satisfied (Yes in step S47), the process is performed. Exit.

  In the above processing, the processing end condition in step S47 can be arbitrarily set in the operation of the correspondence table generating devices 2B and 2B '. For example, there may be a condition that the process is terminated only when both reception of correspondence table information and transmission of correspondence table information are absent, and a condition that the process is terminated even when there is no request for one of them.

  Next, FIG. 12 will be described. FIG. 12 shows a processing method for distributing and arranging correspondence table information of the correspondence table holding device 2B (or 2B ').

  The correspondence table holding device 2B (or 2B ') distributes the correspondence table in each database when a configuration request for the distribution of the correspondence table to the database is generated (Yes in step S50) (step S51). If no request has occurred (No in step S50), the process is terminated.

  The correspondence table DB configuration calculation unit 241 of the correspondence table DB configuration processing unit 24 receives the operation and configuration policy of the configuration method from the correspondence table DB configuration policy management unit 242, and responds to the current own database from the transmission source locator correspondence table DB6. Table information is obtained (step S51).

  Based on the information obtained in step S51, the correspondence table information to be held in its own transmission source locator correspondence table DB 6 or the correspondence table information to be held in another device is calculated according to the configuration method, and the actual correspondence is calculated. The distribution arrangement of the table information is calculated (step S52).

  Based on the result calculated in step S52, the correspondence table information in the transmission source locator correspondence table DB6 managed by itself is changed (step S53).

  Based on the result calculated in step S52 and the correspondence table information changed in step S53, a correspondence table information message (registration type) of correspondence table information held in another device is generated and transmitted to another device. An instruction to change the information is given (step S54).

  As described above, the correspondence table is distributed and arranged in each device around the correspondence table holding device 2B (or 2B '). The distributed arrangement may be realized only by the correspondence table holding device 2B (or 2B ′), the correspondence table holding device 2A (or 2A ′), the correspondence table generating device 1A (or 1A ′), and the transmission source locator correspondence table DB6. You may implement | achieve by the combination. That is, if there is at least one correspondence table holding device 2B (or 2B '), the correspondence table can be distributed. In addition, the distributed arrangement method can also be a method of exchanging arrangement information while the correspondence table holding devices 2B (or 2B ′) are autonomous with each other in a P2P manner, such as DHT. A method of distributing the correspondence table by arranging the correspondence table holding devices 2B (or 2B ′) in a hierarchy is also possible. A centralized method is also possible in which a part of the correspondence table holding device 2B (or 2B ') plays a central role, calculates the distributed arrangement of the correspondence table, and instructs other devices to hold the correspondence table. Whether one of these methods is selected depends on the operation policy of the distributed arrangement of the correspondence table, and therefore the correspondence table DB configuration policy management unit 242 of the correspondence table DB configuration processing unit 24 of the correspondence table holding device 2B (or 2B ′). Given to.

  Also, correspondence table information registration and mapping change notification from the correspondence table generation device 1A (or 1A ′) viewed from the outside of the distribution table of correspondence table information configured by the correspondence table holding device 2B (or 2B ′). A series of operations such as a correspondence table information request from the device 3A and a correspondence table information response to the device are the same as those shown in FIG. That is, in FIG. 9, the correspondence table holding device 2A is simply replaced with a distributed arrangement system constituted by the correspondence table holding device 2B (or 2B ′), and the correspondence table generation device 1A of the locator loc-a and the locator loc- The processing method of the messages 701, 702, 703, etc. as seen from the mapping change notification device 3A of b is the same.

  According to the communication system according to the present embodiment, a relay device such as a router or a server, or a device such as a server for the present invention generates and generates a correspondence table of transmission source locators for transmission source IDs and transmission destination IDs. By distributing and holding the correspondence table among a plurality of apparatuses, it is possible to efficiently and scalablely hold the information of the correspondence table that can be enormous information. That is, in order to realize scalability for applying the present invention to a huge network such as the Internet, when the locator information corresponding to the movement ID is changed due to movement of the end terminal or ID in the huge network, the communication path When notifying the mapping change to optimize the transmission, it is possible to know the transmission source locator as the appropriate mapping change notification destination from the held correspondence table. Therefore, the relay apparatus that performs the mapping change notification can transmit the mapping change notification message to the relay apparatus suitable for communication optimization.

  According to the communication system according to the present embodiment, in the locator ID separation network, it is possible to realize scalable and efficient optimization of the communication path accompanying the movement of the end terminal and the ID. In addition, a telecommunications carrier that realizes a huge network can transmit a mapping change notification message to a desired transmission source locator when operating and managing its own network. Therefore, when an end terminal or ID in the locator ID separation network moves, the communication delay is reduced and the broadband communication band is secured while considering the policy of the network that receives the mapping change notification. Can be used effectively) and the connection of the communication session can be continued.

(Third embodiment)
A communication system according to a third embodiment of the present invention will be described with reference to the drawings. In the communication system according to the third embodiment, the relay device has the functions of the correspondence table holding devices 2A, 2A ′, 2B, and 2B ′. In this embodiment, since the relay apparatus has the function of the correspondence table holding apparatus, the mapping change notification apparatus can transmit the mapping change notification to an appropriate mapping change notification destination only by exchanging with the relay apparatus.

  FIG. 13 shows a network example in which the relay device has the function of the correspondence table holding device. Referring to FIG. 13, the relay device of locator loc-a having the function of correspondence table generating device 1A holds correspondence table information for the relay device of locator loc-d having the function of correspondence table holding device 2A. The relay device of the locator loc-b having the function of the mapping change notification device 3A requests the correspondence table information to the relay device of the locator loc-d and receives a response.

  The relay device of locator loc-a registers correspondence table information indicating the source locator loc-a having the transmission source ID of ID ID-1 and the transmission destination ID of ID ID-2 with the relay device of locator loc-d. Thus, the registration type correspondence table information message is transmitted (704 in FIG. 13), and the relay device of the locator loc-d holds the received correspondence table information. At this time, the relay device of locator loc-a gives mapping information of ID ID-1 to other networks, “ID ID-1 is locator loc-a, loc-d, and locator loc-d has priority. ”And know that you ’re advertising. That is, the relay device of locator loc-a uses the information in the correspondence table whose source ID is ID ID-1 as the correspondence device of ID ID-1 to the relay device of locator loc-d advertising the mapping information. Instruct them to register.

  When the relay device of locator loc-b optimizes the communication path with ID ID-1 regarding the movement of ID ID-2, the relay device of locator loc-d is referred to the mapping information 82 held by itself. Then, a request type correspondence table information message for determining the transmission destination of the mapping change notification message is transmitted (705 in FIG. 13).

  In response to the request, the relay device of locator loc-d sends a response type correspondence table information message including information on the transmission source locator loc-a, which is the corresponding locator, from the correspondence table information held in locator loc-b. To the relay device (706 in FIG. 13).

  The relay device of locator loc-b that has obtained the transmission source locator information of ID ID-1 transmits a mapping change notification message to the relay device of locator loc-a (401 in FIG. 13).

  The relay device of locator loc-a that has received the mapping change notification message changes the mapping information related to ID ID-2 from “ID ID-2 is locator loc-b” to “ID ID-2 is locator loc-c”. .

  In the above communication operation, the correspondence table information included in the message 704 is the same as the message 701 in FIG. 9, the correspondence table information included in the message 705 is the same as the message 702 in FIG. The correspondence table information included in the message is the same as the message 703 in FIG. The difference is the destination and source of the message. Further, the relay device of locator loc-d may be one device in a distributed table of correspondence tables configured mainly with relay device 2B (or 2B ').

  In the above communication operation example, when the relay device of locator loc-d receives the mapping change notification message instead of the request type correspondence table information message 705 from the relay device of locator loc-b, the information of the mapping change notification message The correspondence table information may be retrieved and referenced, and the mapping change message may be transferred to the relay device of the locator loc-a, which is a transmission destination relay measure for an appropriate mapping change notification message, using the obtained correspondence table information. . That is, destination locator (D-loc) 41 is locator loc-d, source locator (S-loc) 42 is locator loc-b, mapping change ID 43 is ID ID-2, and corresponding locator 44 is locator loc-c. When a mapping change notification message is received, a locator corresponding to any combination of source IDs whose destination ID is ID ID-2 is obtained from the correspondence table, and a destination locator (D-loc) 41 is obtained. The same mapping change notification message is sent to the locator. At this time, the mapping change notification message is transferred to the relay device of locator loc-a.

  In this case, since the mapping change notification message is transferred to the locator corresponding to any combination of the transmission source IDs having the transmission destination ID ID-2, it cannot be transmitted only to the relay device of the transmission source locator relating to the ID ID-1. . On the other hand, when the relay device of locator loc-d receives a request type correspondence table information message 705 in addition to the mapping change notification message from the relay device of locator loc-b, the mapping information is determined from the mapping change notification message information. The change ID (ID ID-2) and the changed locator information (locator loc-c) are known, and the correspondence table information message 705 indicates the source ID (ID ID-1) that is the target of the mapping change notification message. Know the information. Therefore, based on the correspondence table information held by locator loc-d, the relay device of locator loc-d can directly notify the relay device of locator loc-a of the mapping change.

  As described above, the relay device such as the router or the server holds the correspondence table according to the present invention, so that the mapping change notification device determines the transmission destination of the appropriate mapping change notification message by exchanging messages only with the relay device. Obtainable. In addition, by making the relay device that registers the correspondence table a relay device that corresponds to the mapping information advertised to the network, the mapping change notification message is sent from the correspondence table information to the appropriate mapping change notification based on its own mapping information. The destination of the message can be obtained.

  According to the communication system according to the present embodiment, it is possible to realize scalable and efficient optimization of a communication path associated with movement of an end terminal or an ID even in a network in which mapping information in the locator ID separation network is asymmetric. it can. Further, according to the communication system according to the present embodiment, the mapping change notification message can be transmitted to the desired transmission source locator in the network on the correspondence table generating side. Therefore, when an end terminal or ID in the locator ID separation network moves, the communication delay is reduced and the broadband communication band is secured while considering the policy of the network that receives the mapping change notification. Can be used effectively) and the connection of the communication session can be continued.

  Although the above description has been made based on the embodiment, the present invention is not limited to the above embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

1, 2 Identifier (ID)
1A, 1A ′ Corresponding table generating device 11 Corresponding table managing unit 111 Corresponding table generating unit 112 Corresponding table registering unit 12 Policy managing unit 121 Policy receiving unit 122 Policy storing unit 13 External connection interface 2A, 2A ′ Corresponding table holding device 21 Corresponding table DB change processing unit 211 Corresponding table DB changing unit 212 Corresponding table DB referring unit 213 Corresponding table DB searching unit 22 Corresponding table information transmitting / receiving unit 221 Corresponding table information receiving unit 222 Corresponding table information transmitting unit 23 External connection interface 3A Mapping change notification device 31 Locator information acquisition unit 311 Corresponding locator reference request unit 312 Corresponding locator information acquisition unit 32 Mapping change notification unit 321 Change notification message generation unit 33 Packet transmission / reception unit 331 Packet reception unit 332 Packet transmission unit 34 External connection interface 4A Mapping change notification message format Matt 41 destination locator (D-loc)
42 Source Locator (S-loc)
43 Mapping change ID
44 Corresponding locator groups 401 to 404 Mapping change message notification example 5A Transmission source locator correspondence table 6 Transmission source locator correspondence table DB
7A Correspondence table information message 71 Message type 72 Destination ID
73 Sender ID
74 Source locator groups 701 to 706 Correspondence table information message notification examples 81 to 89, 810 Mapping information 91 to 96 Communication path (packet flow)
101-105 Packet header loc-a-loc-d Locator ID ID-1, ID ID-2 Identifier (ID)

Claims (17)

Holding a correspondence table associating a pair of a transmission source ID and a transmission destination ID of a packet with a transmission source locator of the packet;
When the mapping information between the transmission destination ID and the transmission destination locator is changed, the transmission source locator associated with the transmission destination ID is extracted with reference to the correspondence table and included in the transmission source locator. A mapping information notifying device for notifying the packet relay device of the change contents of the mapping information.   The mapping information notification apparatus according to claim 1, wherein the correspondence table is distributed and held among other mapping information notification apparatuses.   When the mapping information between the transmission destination ID and the transmission destination locator is changed, the mapping is performed by referring to the correspondence table distributed and held among a plurality of mapping information notification devices. 3. The mapping information notification device according to claim 2, wherein a source locator is extracted, and the change contents of the mapping information are notified to a packet relay device included in the source locator.   The mapping information notification device according to claim 1, wherein the packet is relayed.   A communication system comprising the mapping information notification device according to any one of claims 1 to 4.   A correspondence table generating device that generates a correspondence table that associates a pair of a packet transmission source ID and a transmission destination ID with a transmission source locator of the packet, and transmits the correspondence table to the mapping information notification device; The communication system according to claim 5, wherein the communication system is characterized.   The communication system according to claim 6, wherein the correspondence table generation device relays a packet. A step of storing a correspondence table associating a pair of a transmission source ID and a transmission destination ID of a packet with a transmission source locator of the packet in a storage device;
When mapping information between a transmission destination ID and a transmission destination locator is changed, referring to the correspondence table, extracting a transmission source locator associated with the transmission destination ID;
And a step of notifying the packet relay apparatus included in the extracted transmission source locator of the change contents of the mapping information.   9. The mapping information notification method according to claim 8, further comprising the step of the computer distributing and holding the correspondence table with other computers. When the mapping information between the transmission destination ID and the transmission destination locator is changed, the computer is associated with the transmission destination ID with reference to the correspondence table distributed and held among a plurality of computers. Extracting a source locator; and
The mapping information notification method according to claim 9, further comprising a step of notifying a packet relay apparatus included in the extracted transmission source locator of the change contents of the mapping information.   The mapping information notification method according to any one of claims 8 to 10, further comprising a step of relaying the packet by the computer. A computer generating a correspondence table associating a pair of a transmission source ID and a transmission destination ID of a packet with a transmission source locator of the packet;
The mapping information notification method according to claim 8, further comprising a step of transmitting the correspondence table to another computer. A process of holding a correspondence table associating a pair of a packet transmission source ID and a transmission destination ID with a transmission source locator of the packet in a storage device;
When mapping information between a transmission destination ID and a transmission destination locator is changed, a process of extracting a transmission source locator associated with the transmission destination ID with reference to the correspondence table;
A program causing a computer to execute a process of notifying a packet relay apparatus included in an extracted transmission source locator of the change contents of the mapping information.   The program according to claim 13, further causing the computer to execute processing for distributing and holding the correspondence table with other computers. When mapping information between a transmission destination ID and a transmission destination locator is changed, a transmission source locator associated with the transmission destination ID with reference to the correspondence table distributed and held among a plurality of computers The process of extracting
15. The program according to claim 14, further causing the computer to execute a process of notifying the packet relay device included in the extracted transmission source locator of the change information of the mapping information.   The program according to any one of claims 13 to 15, further causing a computer to execute a process of relaying a packet. A process of generating a correspondence table that associates a pair of a transmission source ID and a transmission destination ID of a packet with a transmission source locator of the packet;
The program according to any one of claims 13 to 16, further causing a computer to execute a process of transmitting the correspondence table to another computer.

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