JP4440057B2 - Communication management system and communication management apparatus - Google Patents

Description

  The present invention relates to a communication management system and a communication management apparatus that perform location registration of a mobile terminal and transfer of user packets.

  With the development of communication technology, mobile communication terminals such as PHS (Personal Handyphone System) and PDA (Personal Digital Assistant) are being developed. Mobile IP or the like is used as means for continuing communication without interruption while maintaining the same IP (Internet Protocol) address while a communication terminal moves.

  For example, in the case of a PHS or a mobile phone using Mobile IPv6, the communication terminal (telephone) processes the IP protocol using information on which location is located (information on which base station is connected) as a location registration packet. To a mobile switching center (MSC) such as a router. The router or the like registers (location registration) information on where the communication terminal is located in a database for each communication terminal. The router determines the transfer path of the user packet based on the location registration registered in the database and performs encapsulation specific to the mobile IP. That is, a router that performs IP protocol processing performs location registration and user packet transfer with the same device.

  In addition, there is a technique for distributing the load to the server in order to enable high-speed communication between the server and the client. By placing a load balancer (load distribution control device) on the front end of a plurality of servers, the load balancer monitors the loads on the plurality of servers. Then, packets are evenly distributed to a plurality of load distribution target servers based on information on monitoring of server load (for example, Patent Document 1).

JP 2003-174473 A

  However, according to the above conventional technique, the router that processes the IP protocol performs the processing of the location registration packet and the transfer of the user packet by the same device, so the movement frequency of the communication terminal is high and the traffic of the location registration packet increases. In this case, it is necessary to install another mobile IP router regardless of the traffic volume of user packets.

  In addition, when load balancing control devices are arranged at the front ends of a plurality of mobile IP routers, it is necessary to transfer the location registration packet and the user packet from the communication terminal to the same mobile IP router when processing the mobile IP protocol. There is a problem that it is impossible to individually cope with an increase in traffic of location registration packets and an increase in traffic of user packets.

  In addition, Mobile IP uses encryption procedures such as IPSEC (Security Architecture for the Internet Protocol) for terminal authentication and data protection, but it can encode / decode both location registration packets and user data at high speed. No technique is disclosed that individually handles the increase in traffic of location registration packets and the increase in traffic of user packets while processing.

  The present invention has been made in view of the above, and an object of the present invention is to obtain a communication management system and a communication management apparatus capable of efficiently processing location registration of a mobile terminal and transmission / reception of user data.

  In order to solve the above-described problems and achieve the object, the present invention provides a communication management system having a home agent function for managing information on the location of a mobile terminal and transferring user packets transmitted and received by the mobile terminal. A location management device having a location management unit that manages information related to the location of the mobile terminal based on location registration information related to the location of the mobile terminal transmitted from the mobile terminal, and the location registration information transmitted by the mobile terminal as the location The location response information transmitted by the location management device as response information to the location registration information is forwarded to the mobile terminal, and user packets transmitted and received by the mobile terminal are not passed through the location management device. A transfer unit that transfers to the location, and the transfer unit includes the location registration information, the location response information, and the user. When transferring packet, the location registration information, characterized in that it comprises a communication management apparatus having a cryptographic processing unit for the position response information and the user packet is encrypted or decrypted.

  According to the present invention, since the communication management apparatus manages the control parameters for encryption of information transmitted from the mobile terminal, the position management apparatus needs to manage the control parameters for encryption of information transmitted from the mobile terminal. Disappear.

  According to the present invention, it is not necessary for the location management device to manage control parameters for encryption of information transmitted from the mobile terminal, and thus the location management device can quickly perform location registration processing of the mobile terminal. There is an effect.

  Embodiments of a communication management system and a communication management apparatus according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of a communication management system according to Embodiment 1 of the present invention. The communication management system includes one to a plurality of mobile terminals 1, a plurality of access routers 21 and 22, a relay router 3, a communication management device 4, a communication terminal 6, and a server (location management device) 7.

  Since the plurality of mobile terminals 1 have the same configuration (function) and perform the same operation, the plurality of access routers 21 and 22 have the same configuration and perform the same operation. A case where there are one mobile terminal 1 and one access router 21 and 22 in the system will be described.

  The mobile terminal 1 is a communication terminal such as a mobile phone or a PHS (Personal Handyphone System) that performs location registration with the server 7 using a mobile IP (Internet Protocol) protocol when moving. The mobile terminal 1 transmits and receives information (user packets) to and from the communication terminal 6 via the access routers 21 and 22 and the relay router 3. The communication terminal 6 is a terminal that performs communication with the mobile terminal 1 such as a personal computer that transmits and receives user packets.

  The access router 21 is connected to the mobile terminal 1 by wireless communication or the like, and the access router 22 is connected to the communication terminal 6. The access routers 21 and 22 transfer packets transmitted and received between the mobile terminal 1, the communication terminal 6, the communication management device 4, and the like. The access router 21 notifies (transmits) a router advertisement including a network prefix to the mobile terminal 1 at a predetermined cycle so that the mobile terminal 1 can perform location registration with the server 7.

  The relay router 3 is connected to the access routers 21 and 22 and the communication management device 4 and transfers (relays) packets transmitted and received between the access routers 21 and 22 and the communication management device 4 (server 7).

  The communication management device 4 is a device (node) that performs packet transfer processing among the home agent functions defined by the mobile IP. The server 7 is a device that terminates a location registration packet 91 for performing location registration of the mobile terminal 1 in the home agent function defined by the mobile IP. The server 7 causes the communication management apparatus to perform mobile IP encapsulation of user packets transmitted and received between the mobile terminal 1 and the communication terminal 6.

  In the first embodiment, the home agent function is achieved by the server 7 and the communication management device 4. The server 7 and the communication management apparatus 4 constituting the home agent have the same network prefix, and the communication path is set so that the communication management apparatus 4 is located in the middle of the communication path between the mobile terminal 1 and the server 7. ing.

  FIG. 2 is a block diagram illustrating a configuration of the communication management apparatus according to the first embodiment. The communication management device 4 includes a location registration response packet receiver 46, a location registration packet transmitter 45, an IPSEC (Security Architecture for the Internet Protocol) decoder 43, an IPSEC encoder 44, a user packet transfer unit 47, and a communication I / F unit. 41, 42, 48 and a control unit 49. Here, the location registration response packet receiver 46, the location registration packet transmitter 45, and the user packet transfer unit 47 correspond to the transfer unit described in the claims. The IPSEC decoding unit 43 and the IPSEC encoding unit 44 here correspond to the encryption processing unit described in the claims.

  The IPSEC decoding unit 43 decodes the packet encrypted by the mobile terminal 1 based on the IPSEC (encrypting security payload (ESP) specified in RFC (Request For Comments) 2406) or the like. The IPSEC encoding unit 44 encrypts a packet to be transmitted to the mobile terminal 1 by IPSEC.

  The location registration packet transmission unit 45 extracts the location registration packet 91 from the packets decoded by the IPSEC decoding unit 43, and transfers (transmits) the extracted location registration packet 91 to the server 7 via the communication I / F unit 48. To do.

  The location registration response packet receiving unit 46 receives response information (location registration response packet) for the location registration packet 91 from the server 7 via the communication I / F unit 48 and sends it to the IPSEC encoding unit 44.

  The user packet transfer unit 47 extracts a user packet from the packets decoded by the IPSEC decoding unit 43, and transfers the user packet according to preset route information. The user packet transfer unit 47 transfers the user packet addressed to the mobile terminal 1 received from the communication terminal 6 to the IPSEC encoding unit 44.

  The communication I / F unit 42 is a communication interface that transmits and receives information (packets) to and from the mobile terminal 1 via the relay router 3 and the access router 22. The communication I / F unit 41 is a communication interface that transmits and receives information to and from the communication terminal 6 via the relay router 3 and the access router 21. The communication I / F unit 48 is a communication interface that transmits and receives information to and from the server 7.

  The control unit 49 controls the location registration response packet receiving unit 46, the location registration packet transmitting unit 45, the IPSEC decoding unit 43, the IPSEC encoding unit 44, the user packet transfer unit 47, and the communication I / F units 41, 42, and 48.

  FIG. 3 is a block diagram illustrating a configuration of the server according to the first embodiment. The server 7 includes a communication I / F unit 71, an address correspondence table creation unit 72, a care-of address setting instruction unit 73, a response unit 74, and a control unit 79. The address correspondence table creation unit 72 and the care-of address setting instruction unit 73 correspond to the location management unit described in the claims.

  The address correspondence table creation unit 72 creates a correspondence table between the home address of the mobile terminal 1 included in the location registration packet 91 and the care-of address used by the mobile terminal 1 at the destination. The care-of address setting instruction unit 73 instructs the communication management device 4 to set the care-of address included in the location registration packet 91 from the mobile terminal 1 as the destination address of the encapsulated packet for the packet addressed to the home address of the mobile terminal 1. Send instruction information.

  The response unit 74 creates a location registration response packet as a response to the location registration packet 91 from the mobile terminal 1. The communication I / F unit 71 is a communication interface that transmits and receives information to and from the communication management device 4. The control unit 79 controls the communication I / F unit 71, the address correspondence table creation unit 72, the care-of address setting instruction unit 73, and the response unit 74.

  Next, the operation procedure of the communication management system will be described. FIG. 4 is a sequence diagram illustrating an operation procedure of the communication management system according to the first embodiment. The address of the server 7 is disclosed (set) as the home agent address to the mobile terminal 1 in advance.

  The access router 22 transmits a router advertisement message at a predetermined cycle. This router advertisement message includes information for inquiring the mobile terminal 1 about location information (network prefix). The network prefix here has a different value depending on the communication path between the mobile terminal 1 and the server 7. Therefore, a router advertisement message including a network prefix having a different value for each access router 22 is transmitted.

  When the mobile terminal 1 monitors the value of the network prefix from the access router 22 (1) and receives a network prefix having a value different from the previously received network prefix value, the mobile terminal 1 moves. to decide.

  When it is determined that the mobile terminal 1 has moved into a communication range of an access router different from the previous access router 22, the mobile terminal 1 encrypts a location registration packet 91 for registering its own location in the server 7 by IPSEC. Transmit to the access router 22. The encryption here is performed by the transport mode ESP or the like. The access router 22 transmits the location registration packet 91 to the communication management device 4 (server 7) via the relay router 3 (21).

  When the communication management device 4 receives a packet addressed to the server 7 transmitted from the mobile terminal 1 via the communication I / F unit 42, the communication management device 4 sends this packet to the IPSEC decoding unit 43. The IPSEC decoding unit 43 performs IPSEC decoding of the packet based on the source address included in the IP header of the received packet and the control parameter of the IPSEC header. The IPSEC decoding unit 43 determines (analyzes) whether or not the IP packet obtained by the decoding process is the location registration packet 91.

  When the mobile IP is IPv6, the IPSEC decoding unit 43 determines that the IP packet is the location registration packet 91 when the mobility header is added to the option header. In addition, when the mobile IP is IPv4, the IPSEC decoding unit 43 determines that the IP packet is the location registration packet 91 when a UDP port number indicating that the location registration packet 91 is attached to the IP packet.

  When the IPSEC decoding unit 43 determines that the IP packet obtained by the decoding process is the location registration packet 91, the IPSEC decoding unit 43 transfers the IP packet (location registration packet 91) to the location registration packet transmission unit 45. The location registration packet transmitter 45 transfers the location registration packet 91 from the communication I / F unit 48 to the server 7 (22).

  The server 7 receives the location registration packet 91 sent from the communication management device 4 via the communication I / F unit 71. Based on the home address of the mobile terminal 1 included in the location registration packet 91 and the care-of address used by the mobile terminal 1 at the destination, the address correspondence table creation unit 72 of the server 7 A correspondence table of care-of addresses used by the terminal 1 at the destination is created (updated) (location registration of the mobile terminal 1).

  The care-of address setting instruction unit 73 of the server 7 instructs the communication management device 4 to set the care-of address included in the location registration packet 91 as the destination address of the encapsulated packet for the packet addressed to the home address of the mobile terminal 1. Send information.

  The response unit 74 of the server 7 creates a location registration response packet as a response to the location registration packet 91 from the mobile terminal 1. The location registration response packet created by the response unit 74 is sent to the mobile terminal 1. The location registration response packet from the response unit 74 is received by the location registration response packet receiving unit 46 of the communication management device 4 via the communication I / F unit 48 (31).

  The location registration response packet received by the location registration response packet receiving unit 46 is sent to the IPSEC encoding unit 44. The IPSEC encoding unit 44 performs IPSEC encoding of the location registration response packet and transmits it to the mobile terminal 1 from the communication I / F unit 42 (32).

  The mobile terminal 1 encapsulates a user packet addressed to the communication terminal 6 that is a communication partner, and sets the home agent address (the IP address of the server 7) as the destination address of the capsule header. The mobile terminal 1 performs IPSEC encoding (tunnel mode ESP for encrypting the encapsulated packet) of the encapsulated user packet, and transmits it to the communication terminal 6.

  The communication management device 4 receives from the mobile terminal 1 via the communication I / F unit 42 a packet in which the destination address of the capsule header is set to the home agent address. A user packet from the mobile terminal 1 is sent to the IPSEC decoding unit 43.

  The IPSEC decoding unit 43 decodes the user packet from the mobile terminal 1 and determines whether or not the decoded user packet is encapsulated. When determining that the decoded packet is encapsulated, the IPSEC decoding unit 43 transfers the packet to the user packet transfer unit 47 (41).

  The user packet transfer unit 47 removes the capsule header of the encapsulated packet sent from the IPSEC decoding unit 43. The user packet transfer unit 47 transmits the packet from which the capsule header has been removed from the communication I / F unit 41 to the communication terminal 6 via the relay router 3 and the access router 21 (42).

  When the communication terminal 6 transmits a user packet to the mobile terminal 1, the user packet is sent to the communication management device 4 (51). The user packet transfer unit 47 of the communication management device 4 encapsulates the user packet received from the communication terminal 6, sets the care-of address of the mobile terminal 1 as the destination address of the capsule header of the encapsulated user packet, and sets the home address as the source address. The agent address (the IP address of the server 7) is set. This user packet is sent from the user packet transfer unit 47 to the IPSEC encoding unit 44. The IPSEC encoding unit 44 performs an IPSEC encoding process (encrypted by tunnel mode ESP) on the user packet from the user packet transfer unit 47, and transmits it to the mobile terminal 1 from the communication I / F unit (52).

  In the first embodiment, the address of the server 7 is disclosed to the mobile terminal 1 as the home agent address. However, the address of the communication management device 4 is disclosed to the mobile terminal 1 as the home agent address. It is good.

  It is to be noted that a position registration packet 91 or a position registration response packet transmitted or received between the communication management device 4 and the server 7 is added to the position registration packet 91 or the position registration response packet by tunnel mode ESP in which a portion other than the capsule header is IPSEC encoded The location registration response packet may be transmitted and received between the communication management device 4 and the server 7. As a result, the IPSEC control parameters between the communication management device 4 and the server 7 do not need to be managed for each mobile terminal 1, so a set of IPSEC control parameters (direction from the communication management device 4 to the server 7, server 7 To the communication management device 4). Therefore, the location registration packet 91 between the communication management device 4 and the server 7 can be protected, and the location registration process of the mobile terminal 1 can be performed at high speed.

  Regardless of whether or not IPSEC is used between the communication management device 4 and the server 7, the communication management device 4 may add a capsule header to the location registration packet 91 from the mobile terminal 1 and transfer it to the server 7. Good. In this case, the server 7 can be arranged in a network having a network prefix with an IP address different from that of the communication management device 4 (a network having a different IP subnetwork).

  As described above, the address of the server 7 is disclosed to the mobile terminal 1 as a home agent, and the communication management device 4 receives the location registration packet 91 addressed to the address of the server 7. Since the communication management device 4 performs IPSEC decoding processing and encoding processing, the server 7 sets the IPSEC control parameters (parameters from the mobile terminal 1 to the home agent and the home agent to the mobile terminal 1 for each mobile terminal). Need to manage parameters in the direction of

  As described above, according to the first embodiment, the server 7 does not need to manage the IPSEC control parameters of the mobile terminal 1, and even if the number of mobile terminals 1 in the communication management system increases, the communication management It becomes possible for the apparatus 4 to quickly perform the IPSEC control parameter search process. Therefore, the server 7 can quickly perform the location registration process of the mobile terminal 1.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, a plurality of servers (servers 85 to 86 described later) are arranged for one communication management device 4 in the communication management system, and the communication management device 4 performs additional distribution of the servers.

  FIG. 5 is a diagram illustrating a configuration of the communication management system according to the second embodiment, and FIG. 6 is a block diagram illustrating a configuration of the communication management device according to the second embodiment. 5 and 6, components that achieve the same functions as those of the communication management system and the communication management device 4 according to the first embodiment shown in FIGS. The description to be omitted is omitted.

  As shown in FIG. 5, the communication management system includes a plurality of mobile terminals 11 to 13, a plurality of access routers 21 and 22, a relay router 3, a communication management device 4, a communication terminal 6, and a plurality of servers 85 to 86. Here, the mobile terminals 11 to 13 achieve the same function as the mobile terminal 1 described in the first embodiment, and the servers 85 to 86 achieve the same function as the server 7 described in the first embodiment.

  As shown in FIG. 6, the communication management device 4 includes a location registration response packet receiving unit 46, a location registration packet transmitting unit 45, an IPSEC decoding unit 43, an IPSEC encoding unit 44, a user packet transfer unit 47, and a communication I / F unit 41. , 42, 48, a server addition determination unit 50, a session connection control unit 51, and a control unit 49. Here, the server addition determination unit 50 and the session connection control unit 51 correspond to the first load determination unit described in the claims.

  The server load determination unit 50 monitors the load status of the servers 85 to 86. The server load determination unit 50 selects a server with a low load based on the load status of the servers 85 to 86 and notifies the session connection control unit 51 of the selected server.

  The session connection control unit 51 stores information (registration state) on the location of the mobile terminals 11 to 13 based on the location registration packet 91 from the mobile terminals 11 to 13, and the location registration packet 91 from the mobile terminals 11 to 13 is stored. It is determined whether or not the location of the mobile terminals 11 to 13 is newly registered and whether or not the location is transmitted for location update. Based on the information (notification) from the server load determination unit 50, the session connection control unit 51 selects (manages) the servers (servers 85 to 86) that are the transfer destinations of the location registration packets from the plurality of mobile terminals 11 to 13. The location registration packet 91 is transferred to the selected server.

  Next, an operation procedure of the communication management system according to the second embodiment will be described. FIG. 7 is a sequence diagram illustrating an operation procedure of the communication management system according to the second embodiment. Information indicating the addresses of the servers 85 to 86 (address indicating the server group, identification information indicating the server group, etc.) is disclosed in advance to the mobile terminals 11 to 13 as the home agent address.

  The access router 22 transmits a router advertisement message at a predetermined cycle. The mobile terminals 11 to 13 monitor the value of the network prefix from the access router 22 (1). When the mobile terminal 11 receives a network prefix having a value different from the network prefix value received previously, the mobile terminal 1 moves. Judge that

  When it is determined that the mobile terminal 1 has moved to an access router different from the previous access router 22, the mobile terminal 1 encrypts the location registration packet 91 by IPSEC (transport mode ESP) and the communication management device 4 (home agent) ((211), ((221), (231)).

  The IPSEC decoding unit 43 of the communication management device 4 performs IPSEC decoding of the packet based on the source address included in the IP header of the received packet and the control parameter of the IPSEC header. The IPSEC decoding unit 43 determines whether or not the IP packet obtained by the decoding process is the location registration packet 91.

  When the IPSEC decoding unit 43 determines that the IP packet obtained by the decoding process is the location registration packet 91, the IPSEC decoding unit 43 transfers the location registration packet 91 to the location registration packet transmission unit 45. The location registration packet transmitter 45 transfers this location registration packet 91 to the session connection controller 51 ((212), (222) (232)).

  The session connection control unit 51 determines that the location registration packet 91 from the mobile terminals 11 to 13 indicates the location of the mobile terminals 11 to 13 based on the information (registration state) related to the locations of the mobile terminals 11 to 13 recorded in advance. It is determined whether it is a location registration packet 91 for newly registering or a location registration packet 91 for updating the location of mobile terminals 11-13.

  When the session connection control unit 51 determines that the position registration packet 91 is a position registration packet 91 for newly registering the positions of the mobile terminals 11 to 13, the session connection control unit 51 newly registers the positions of the mobile terminals 11 to 13. The server load determination unit 50 is notified that the location registration packet 91 has been received.

  The server load determination unit 50 transmits information related to the load status of the servers 85 to 86 (such as information on a server with a small load) to the session connection control unit 51. Based on the information from the server load determination unit 50, the session connection control unit 51 selects a server as a transmission destination of the location registration packet 91 from the servers 85 to 86.

  In the session connection control unit 51, if a correspondence table (address correspondence table) between the addresses of the mobile terminals 11 to 13 and the addresses of the servers 85 to 86 that perform location registration processing has already been created, it is based on the created address correspondence table. Then, the location registration packet 91 is transferred to the addresses of the servers 85 to 86 in the address correspondence table.

  When a packet requesting cancellation of location registration (the lifetime included in the location registration packet is set to 0) is received, or when the servers 85 to 86 receive the location registration packet 91 from the mobile terminals 11 to 13 When information related to the location registration cancellation instruction notified from the servers 85 to 86 due to the absence of time reception is received, the entries of the corresponding mobile terminals 11 to 13 are deleted from the address correspondence table.

  For example, the session connection control unit 51 selects the server 85 as the transmission destination of the location registration packet 91 from the mobile terminal 11 and selects the server 85 as the transmission destination of the location registration packet 91 from the mobile terminal 11. The server 86 is selected as the transmission destination of the location registration packet 91, and the server 87 is selected as the transmission destination of the location registration packet 91 from the mobile terminal 13. The session connection control unit 51 transmits the location registration packet 91 to the selected transmission destination servers 85 to 86 ((213), (223), (233)).

  The servers 85 to 86 receive the location registration packet 91 sent from the communication management device 4. The address correspondence table creating unit 72 of the servers 85 to 86 determines the home address of the mobile terminal 1 based on the home address of the mobile terminal 1 included in the location registration packet 91 and the care-of address used by the mobile terminal 1 at the destination. A correspondence table of care-of addresses used by the mobile terminal 1 at the destination is created.

  The care-of address setting instruction unit 73 of the server 7 instructs the communication management device 4 to set the care-of address included in the location registration packet 91 as the destination address of the encapsulated packet for the packet addressed to the home address of the mobile terminal 1. Send information. Here, the address setting instruction unit 73 transmits the instruction information to the communication management device 4 based on the correspondence table between the home address of the mobile terminal 1 and the care-of address used by the mobile terminal 1 at the destination.

  The response unit 74 of the server 7 creates a location registration response packet as a response to the location registration packet 91 from the mobile terminal 1. The location registration response packet created by the response unit 74 is sent to the mobile terminals 11 to 13. The location registration response packet from the response unit 74 is received by the location registration response packet receiving unit 46 of the communication management device 4 via the communication I / F unit 48 ((311), (321), (331)).

  The session connection control unit 51 confirms the registration status of the location registration response packet from the servers 85 to 86. If the registration ends normally, the session connection control unit 51 determines the address of the mobile terminals 11 to 13 and the address of the servers 85 to 86 that perform location registration processing. Create a correspondence table (address correspondence table). The session connection control unit 51 does not create an address correspondence table if the location registration of the servers 85 to 86 ends abnormally.

  The location registration response packet received by the location registration response packet receiving unit 46 is sent to the IPSEC encoding unit 44 ((312), (322), (332)). The IPSEC encoding unit 44 performs IPSEC encoding of the location registration response packet and transmits it from the communication I / F unit 42 to the mobile terminals 11 to 13 ((313), (323), (333)).

  Next, the load monitoring process and load determination algorithm of the server load determination unit 50 will be described. FIG. 8 is a flowchart illustrating a procedure of server selection processing. The server load determination unit 50 receives from the session connection control unit 51 a notification that the new location registration processing of the mobile terminals 11 to 13 has been normally completed and the addresses of the servers 85 to 86 corresponding to the mobile terminals 11 to 13. (Step S100).

  Based on the information received from the session connection control unit 51, the server load determination unit 50 stores the number of mobile terminals 11 to 13 that are performing location registration processing for each of the servers 85 to 86 (step S110).

  When the session connection control unit 51 receives a new location registration packet from the mobile terminals 11 to 13, the session connection control unit 51 inquires of the server load determination unit 50 about the address of the server (server 85 to 86) serving as a transfer destination of the new location registration packet ( Step S120).

  The server load determination unit 50 compares the number of mobile terminals that are undergoing location registration processing for each server. The server load determination unit 50 selects, for example, a server with the smallest number of mobile terminals that are undergoing location registration processing (a server with a small load) as a server to which a new location registration packet is to be transferred, and sends it to the session connection control unit 51. Notification is made (step S130).

  Thereafter, user packets are transmitted and received between the mobile terminal 11 and the communication terminal 6 by the same processing as in the first embodiment ((41), (42), (51), (52) shown in FIG. 4). The description is omitted.

  In the second embodiment, in step S130 in FIG. 8, the server load determination unit 50 selects the server with the smallest number of mobile terminals that are undergoing location registration processing as the server to which the new location registration packet is to be transferred. However, the server load determination unit 50 may select a server having the smallest number of location registration processes per unit time.

  In this case, the server load determination unit 50 notifies the location registration completion and the addresses of the servers 85 to 86 assigned to the location registration process at the time of location registration update in addition to when the new location registration response is normally completed in step S100. Is received from the session connection control unit 51. Then, the server load determination unit 50 counts the number of position registrations per unit time for each of the servers 85 to 86, and selects the servers 85 to 86 having the smallest number of position registration processes per unit time.

  Further, in step S130 of FIG. 8, the server load determination unit 50 has the smallest number of location registrations per unit time 85 to 86 when the difference in the number of mobile terminals that execute location registration processing is within a predetermined range. It is good also as selecting.

  As described above, a plurality of servers 85 to 86 are arranged for the communication management device 4 constituting the home agent in the communication management system, and the communication management device 4 includes the server load determination unit 50 and the session connection control unit 51. Therefore, the communication management device 4 can select the servers 85 to 86 that execute the location registration process of the mobile terminals 11 to 13 according to the load of the movement registration process of the servers 85 to 86.

  As described above, according to the second embodiment, the communication management device 4 selects the servers 85 to 86 that execute the location registration processing of the mobile terminals 11 to 13 according to the load of the mobile registration processing of the servers 85 to 86. It becomes possible to distribute the load of each server. Therefore, each server can efficiently perform the location registration process of the mobile terminal, and even if the number of mobile terminals increases, the location registration process of the mobile terminal can be performed in a short time.

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described with reference to FIGS. In the third embodiment, a plurality of communication management devices (communication management devices 61 and 62 described later) are arranged for one server 7 in the communication management system, and the server 7 performs additional distribution of the communication management devices.

  FIG. 9 is a diagram illustrating a configuration of the communication management system according to the third embodiment, and FIG. 10 is a block diagram illustrating a configuration of the server according to the third embodiment. 9 and 10, components that achieve the same functions as those of the communication management system and the server 7 according to the first embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and redundant descriptions are given. Is omitted.

  As shown in FIG. 9, the communication management system includes mobile terminals 11 and 12, access routers 21 and 22, a relay router 3, a plurality of communication management devices 61 and 62, a communication terminal 6, and a server 7. The communication management devices 61 and 62 here achieve the same function as the communication management device 4 described in the first embodiment.

  As shown in FIG. 10, the server 7 includes a communication I / F unit 71, an address correspondence table creation unit 72, a care-of address setting instruction unit 73, a response unit 74, a control unit 79, a node selection unit 80, and a node setting management unit 81. Become. The node selection unit 80 and the node setting management unit 81 here correspond to the second load determination unit described in the claims.

  The node setting management unit 81 stores (manages) information related to the settings of the communication management devices 61 and 62. The node setting management unit 81 stores, for each of the communication management devices 61 and 62, information related to the mobile terminals 11 and 12 that perform transfer processing of the location registration packet 91 and the user packet (correspondence relationship between the communication management device and the mobile terminal). The node setting management unit 81 stores, for example, the number of mobile terminals that perform transfer processing of the location registration packet 91 and the user packet for each of the communication management devices 61 and 62.

  Based on the information managed by the node setting management unit 81, the node selection unit 80 is a communication management device (communication management devices 61 and 62) that is a transfer destination of location registration packets and user packets sent from the mobile terminals 11 and 12. Any one).

  Next, the operation procedure of the communication management system will be described. FIG. 11 is a sequence diagram illustrating an address resolution processing procedure according to the third embodiment. Since the mobile terminals 11 and 12 dynamically acquire the home agent address, the destination address is an anycast address (IP layer address) that includes the network prefix of its home network as part of the address at the time of initial activation. A home agent (HA (Home Agent)) search request (packet) set in (1) is transmitted.

  The access router 22 transfers the home agent search request to the relay router 3 based on the anycast address from the mobile terminals 11 and 12. In order to acquire the layer 2 address corresponding to the anycast address from the access router 22, the relay router 3 inquires the communication management devices 61 and 62 for the layer 2 address corresponding to the anycast address (address resolution request for inquiring the layer 2 address). Send a message).

  In response to the address resolution request, both the communication management devices 61 and 62 return an address resolution response including the layer 2 address of the communication management device (communication management devices 61 and 62) to the relay router 3. The address resolution response here is a message including the layer 2 address for the anycast address.

  The relay router 3 receives the address resolution response from the communication management devices 61 and 62. Thereby, the relay router 3 acquires the layer 2 address with respect to the anycast address. For example, the relay router 3 transmits a home agent address search request to the address of the communication management device included in the address resolution response received first. For example, when the relay router 3 first receives an address resolution response from the communication management device 61, the relay router 3 transmits a home agent address search request to the communication management device 61.

  Thereafter, the communication management device 61 transfers a home agent address search request to the server 7. Based on the information stored in the node setting management unit 81, the node selection unit 80 of the server 7 performs information transfer processing (transfer of the location registration packet 91 and the like from the mobile terminal) from the communication management device. The communication management device with the smallest number of mobile terminals is selected.

  The node selection unit 80 selects the communication management device 62, for example. The node selection unit 80 transmits a home agent search response designating the communication management device 62 to the mobile terminals 11 and 12 via the communication management device 61 that has transferred the home agent address search request. The home agent address search response here is a response to the home agent address search request and is a packet including the home agent address.

  Next, transfer procedures for packets transmitted and received by the mobile terminals 11 and 12 will be described. FIG. 12 is a sequence diagram illustrating an operation procedure of the communication management system according to the third embodiment. The access router 22 transmits a router advertisement message at a predetermined cycle (1).

  The mobile terminals 11 and 12 transmit the location registration packet 91 to the communication management device 62 designated by the home agent search response ((611), (621)). Since the communication management device 62 transfers the location registration packet 91 to the server 7 by the same processing procedure as that of the communication management device 4 of the first embodiment ((612), (622)), the description thereof is omitted.

  The node setting management unit 81 of the server 7 stores the number of mobile terminals that perform transfer processing of the location registration packet 91 and the like for each of the communication management devices 61 and 62 based on the location registration packet 91 from the mobile terminals 11 and 12. .

  Further, the server 7 performs location registration of the mobile terminals 11 and 12 according to the same processing procedure as in the first embodiment, and uses the location registration packet 91 as the destination address of the encapsulated packet for the packet addressed to the home address of the mobile terminals 11 and 12 The instruction information is transmitted to the communication management device 62 so as to set the care-of address included in. Further, the server 7 transmits a location registration response (packet) to the communication management device 62 by the same processing procedure as in the first embodiment (613, 623), and the communication management device 62 performs the same processing procedure as in the first embodiment. A location registration response is transmitted to the mobile terminals 11 and 12 ((614), (624)).

  The mobile terminals 11 and 12 transmit user packets to the communication management device 62 designated by the home agent search response ((641) and (661)). The communication management device 62 transfers the user packet to the communication terminal 6 by the same processing procedure as that of the communication management device 4 of the first embodiment ((642), (662)).

  A communication management device that performs transfer processing on user packets transmitted from the communication terminal 6 to the mobile terminals 11 and 12 is set in advance in the relay router 3 or the like. The communication management device that performs the transfer process is set based on, for example, a unique address (home address) of the mobile terminals 11 and 12. For example, the user packet to the mobile terminal 11 is set to be transferred via the communication management device 61, and the user packet to the mobile terminal 12 is set to be transferred via the communication management device 62.

  The user packet from the communication terminal 6 is transmitted to the communication management devices 61 and 62 set in advance via the relay router 3 ((651), (671)). The communication management devices 61 and 62 transmit user packets to the mobile terminals 11 and 12 by the same processing procedure as in the first embodiment ((652) and (672)).

  Note that the server 7 is not limited to the number of mobile terminals for which the communication management devices 61 and 62 perform packet transfer processing, and communication for performing packet transfer processing based on the traffic volume per unit time of the communication management devices 61 and 62. A management device may be selected. In this case, the communication management devices 61 and 62 notify the server 7 of the traffic volume per unit time.

  As described above, the plurality of communication management devices 61 and 62 are arranged for the server 7 constituting the home agent in the communication management system, and the server 7 includes the node selection unit 80 and the node setting management unit 81. The server 7 can select the communication management devices 61 and 62 for executing the packet transfer processing from the mobile terminals 11 and 12 according to the load of the communication management devices 61 and 62.

  As described above, according to the third embodiment, the server 7 selects the communication management devices 61 and 62 that execute the packet transfer processing from the mobile terminals 11 and 12 according to the load of each communication management device 61 and 62. The load of the communication management apparatus can be distributed, and each communication management apparatus can efficiently perform packet transfer processing. Therefore, even when the number of mobile terminals increases or when traffic between the mobile terminals and the communication terminal 6 increases, it is possible to perform mobile terminal location registration processing and user packet transfer processing in a short time. It becomes.

Embodiment 4 FIG.
Next, a fourth embodiment of the present invention will be described with reference to FIGS. In the fourth embodiment, in the communication management system or the like according to the third embodiment, a communication management device that returns an address resolution response to an address resolution request (anycast address) from the relay router 3 is set. In the fourth embodiment, the node selection unit 80 of the server 7 selects a communication management device that returns an address resolution response request.

  The configuration of the communication management devices 61 and 62 according to the fourth embodiment will be described. Since the communication management devices 61 and 62 have the same configuration, the communication management device 61 will be described here as an example.

  FIG. 13 is a block diagram showing a configuration of the communication management apparatus according to the fourth embodiment, and a configuration that achieves the same function as the communication management apparatus 4 of the first embodiment shown in FIG. Elements are given the same numbers, and duplicate descriptions are omitted.

  As illustrated in FIG. 13, the communication management device 61 includes a location registration response packet receiver 46, a location registration packet transmitter 45, an IPSEC decoder 43, an IPSEC encoder 44, a user packet transfer unit 47, and a communication I / F unit 41. , 42, 48, a response transmission setting unit 55, and a control unit 49.

  The response transmission setting unit 55 sets whether to return an address resolution response request to the anycast address based on the instruction information from the server 7. The response transmission setting unit 55 returns an address resolution response when it receives an address resolution request from the relay router 3 when it is set to return an address resolution response to the anycast address.

  FIG. 14 is a sequence diagram illustrating an address resolution processing procedure according to the fourth embodiment. The node selection unit 80 of the server 7 transmits in advance instruction information (response transmission permission information) for permitting the reply of the address resolution response request to one of the communication management devices 61 and 62. The server 7 transmits response transmission permission information to the communication management device 61, for example. When the response transmission setting unit 55 of the communication management device 61 receives the response transmission permission information from the server 7, it sets the address resolution response to be returned in response to the address resolution request (anycast address) from the relay router 3.

  The mobile terminals 11 and 12 transmit an HA (home agent) search request to the server 7 in order to dynamically acquire the home agent address. The home agent search request from the mobile terminals 11 and 12 to the server 7 is received by the relay router 3.

  The relay router 3 transmits an address resolution request in which the broadcast address is set as the destination address in order to acquire the layer 2 address corresponding to the anycast address from the access router 22.

  Of the communication management devices 61 and 62 that have received the address resolution request from the relay router 3, the communication management device 61 that can send an address resolution response to the anycast address sets its own layer 2 address in the address resolution response. The address resolution response is transmitted to the relay router 3.

  When receiving the address resolution response from the communication management device 61, the relay router 3 transmits a home agent address search request to the address of the communication management device 61 included in the address resolution response. The response transmission setting unit 55 of the communication management device 61 sets its own IP address in the home agent address search response, and transmits this home agent address search response to the mobile terminals 11 and 12 via the relay router 3.

  When the relay router 3 obtains the layer 2 address corresponding to the anycast address by the address resolution response, the relay router 3 does not store the correspondence (correspondence table) between the anycast address and the layer 2 address.

  The node setting management unit 81 of the server 7 monitors the traffic per unit time for each of the communication management devices 61 and 62 and the number of mobile terminals performing location registration processing. When the node selection unit 80 of the server 7 determines that the processing load of the communication management device 62 is smaller than the processing load of the communication management device 61 based on the information managed by the node setting management unit 81, the node selection unit 80 sets the anycast address. On the other hand, instruction information (response transmission cancellation information) that does not permit the reply of the address resolution response (cancel the permission of the address resolution response) is transmitted to the communication management device 61. At this time, response transmission permission information is transmitted to the communication management device 62.

  The response transmission setting unit 55 of the communication management device 61 sets the address resolution response not to be returned to the anycast address. The response transmission setting unit 55 of the communication management device 62 performs setting so as to return an address resolution response to the anycast address.

  Thereafter, the mobile terminals 11 and 12 transmit a home agent search request to the server 7 in order to dynamically acquire the home agent address. The home agent search request from the mobile terminals 11 and 12 to the server 7 is received by the relay router 3. Then, the relay router 3 transmits an address resolution request in which the broadcast address is set as the destination address in order to acquire the layer 2 address corresponding to the anycast address from the access router 22.

  Since the relay router 3 does not store the correspondence between the anycast address and the layer 2 address, the relay router 3 transmits an address resolution request every time a packet including the anycast address as a destination address is received.

  Of the communication management devices 61 and 62 that have received the address resolution request from the relay router 3, the communication management device 62 that can return an address resolution response to the anycast address sets its own layer 2 address in the address resolution response. This address resolution response is transmitted to the relay router 3.

  When receiving the address resolution response from the communication management device 62, the relay router 3 transmits a home agent address search request to the address of the communication management device 62 included in the address resolution response. The response transmission setting unit 55 of the communication management device 62 sets its own IP address in the home agent address search response, and transmits this home agent address search response to the mobile terminals 11 and 12 via the relay router 3.

  In this way, each communication management device 61, 62 sets whether to transmit an address resolution response and a home agent search response to the relay router 3 based on the response transmission permission information and the response transmission release information from the server 7. Therefore, the relay router 3 can receive the address resolution response and the home agent search response from a predetermined communication management device without storing the correspondence table between the layer 2 address and the anycast address.

  As described above, according to the fourth embodiment, the server 7 selects the communication management devices 61 and 62 that execute the packet transfer processing from the mobile terminals 11 and 12 according to the load of each communication management device 61 and 62. The load of the communication management apparatus can be distributed, and each communication management apparatus can efficiently perform packet transfer processing. Therefore, even when the number of mobile terminals increases or when traffic between the mobile terminals and the communication terminal 6 increases, it is possible to perform mobile terminal location registration processing and user packet transfer processing in a short time. It becomes.

  As described above, the communication management system and the communication management apparatus according to the present invention are suitable for location registration of a mobile terminal and transfer of user packets.

1 is a diagram showing a configuration of a communication management system according to Embodiment 1. FIG. 1 is a block diagram illustrating a configuration of a communication management apparatus according to Embodiment 1. FIG. 2 is a block diagram illustrating a configuration of a server according to Embodiment 1. FIG. FIG. 3 is a sequence diagram showing an operation procedure of the communication management system according to the first embodiment. It is a figure which shows the structure of the communication management system which concerns on Embodiment 2. FIG. 6 is a block diagram illustrating a configuration of a communication management apparatus according to Embodiment 2. FIG. FIG. 10 is a sequence diagram showing an operation procedure of the communication management system according to the second embodiment. It is a flowchart which shows the procedure of the selection process of a server. FIG. 10 illustrates a configuration of a communication management system according to a third embodiment. FIG. 10 is a block diagram illustrating a configuration of a server according to a third embodiment. FIG. 10 is a sequence diagram illustrating an address resolution processing procedure according to the third embodiment. FIG. 10 is a sequence diagram showing an operation procedure of the communication management system according to the third embodiment. FIG. 10 is a block diagram illustrating a configuration of a communication management device according to a fourth embodiment. FIG. 10 is a sequence diagram illustrating an address resolution processing procedure according to the fourth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11-13 Mobile terminal 3 Relay router 4,61,62 Communication management apparatus 6 Communication terminal 7,85-87 Server 21,22 Access router 41,42,48,71 Communication I / F part 43 IPSEC decoding part 44 IPSEC Encoding unit 45 Location registration packet transmission unit 46 Location registration response packet reception unit 47 User packet transfer unit 49, 79 Control unit 50 Server load determination unit 51 Session connection control unit 55 Response transmission setting unit 72 Address correspondence table creation unit 73 Address setting instruction Unit 74 Response unit 79 Control unit 80 Node selection unit 81 Node setting management unit 91 Location registration packet

Claims (9)

In a communication management system having a home agent function for managing information on the position of a mobile terminal and transferring user packets transmitted and received by the mobile terminal,
A location management device having a location management unit that manages information related to the location of the mobile terminal based on location registration information related to the location of the mobile terminal transmitted from the mobile terminal by mobile IP ;
The location registration information transmitted by the mobile terminal is transferred to the location management device, the location response information transmitted by the location management device as response information to the location registration information is forwarded to the mobile terminal, and the mobile terminal A transfer unit that transfers user packets transmitted and received without passing through the location management device, and the transfer unit transfers the location registration information, the location response information, and the user packet when the location registration information, the location An encryption processing unit that encrypts or decrypts response information and the user packet;
A communication management system comprising:   The communication management system according to claim 1, wherein transmission / reception of the location registration information and the location response information between the location management device and the communication management device is performed by an encrypted tunnel path. The location management device and the mobile terminal each include a plurality, and the communication management device further includes a first load determination unit that determines a load state for each location management device,
The first load determination unit selects, for each mobile terminal , a location management device that transmits and receives the location registration information and the location response information to and from the mobile terminal based on the load state. The communication management system according to claim 1 or 2.   The first load determination unit is configured to determine a number of mobile terminals that each location management device transmits and receives the location registration information and the location response information, or the number of times the location registration information is processed per unit time of each location management device. The communication management system according to any one of claims 1 to 3, wherein a load state of each position management device is determined based on at least one. The communication management device and the mobile terminal each include a plurality, and the location management device further includes a second load determination unit that determines a load state for each communication management device,
The second load determination unit transmits a communication management device that transmits and receives the location registration information, the location response information, and the user packet to and from the mobile terminal based on a load state of each communication management device. Select every
Each said mobile terminal transmits / receives the said location registration information, the said location response information, and a user packet between the communication management apparatuses for every said mobile terminal selected by the said 2nd load judgment part. Item 3. The communication management system according to Item 1 or 2.   The second load determination unit instructs the mobile terminal to transmit / receive the location registration information, the location response information, and a user packet to / from the communication management device selected by the second load determination unit. The communication management system according to any one of claims 1, 2, and 5, wherein:   The second load determination unit, for each communication management device selected for each mobile terminal, the location registration information, the position response information, and the mobile terminal selected by the second load determination unit. The communication management system according to claim 1, wherein the instruction information is transmitted so as to transmit and receive a user packet.   The second load determination unit includes: the number of mobile terminals that each communication management device transmits / receives the location registration information, the location response information, and the user packet; and the location registration information per unit time of each communication management device. The load state of each communication management device is determined based on at least one of the number of processing times or the amount of traffic per unit time of each communication management device. The communication management system according to any one of the above. The position management device is arranged between a location management device that manages information related to the location of the mobile terminal based on location registration information related to the location of the mobile terminal transmitted from the mobile terminal by the mobile IP, and the location management device. In a communication management device that performs communication management between the mobile terminals,
The location registration information transmitted by the mobile terminal is transferred to the location management device, the location response information transmitted by the location management device as response information to the location registration information is forwarded to the mobile terminal, and the mobile terminal A transfer unit that transfers user packets transmitted and received without passing through the location management device;
An encryption processor that encrypts or decrypts the location registration information, the location response information, and the user packet when the transfer unit transfers the location registration information, the location response information, and the user packet;
A communication management device comprising: