JP2010062933A - Relay server, and relayed communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for facilitating flexible operation for setting a communication system in each section to be an independent system in a relayed communication system, where remote LANs communicate beyond WANs. <P>SOLUTION: Relay servers 12, 22 relay mutual communication between client terminals 11, 21. The relay server 12 (22) creates information shown below to allow the entire relayed communication system to share the information, namely relay group information indicating that the relay servers 12, 22 compose a relay group and relay server information indicating the client terminal 11 (21) communicable with the relay server 12 (22). The relay servers 12, 22 check identification information designated as a destination with that mentioned in the relay group information and the relay server information, thus deciding a transfer destination. The relay servers 12, 22 decide an address setting system and an encryption communication setting system based on the transfer destination. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a relay server and a relay communication system that enable a client terminal connected to a remote LAN (Local Area Network) to communicate over a WAN (Wide Area Network).

  A client terminal connected to a remote LAN may communicate over a WAN. A VPN (Virtual Private Network) can construct a network as if a remote LAN is directly connected. However, it is difficult for VPN to build a scalable and flexible network.

  The relay communication system disclosed in Patent Document 1 can construct a network as if a remote LAN is directly connected, like VPN. And unlike a VPN, a relay communication system is easy to construct a network with expandability and flexibility.

  The relay communication system includes a WAN and a plurality of LANs. Each LAN includes a relay server. Each relay server stores relay group information about a relay server included in the relay communication system and shared resource information about a resource shared by the relay communication system.

  When a client terminal connected to one LAN operates a resource stored in a client terminal connected to another LAN, the relay server connected to these LANs is based on the relay group information and the shared resource information. , Relay resource operations.

  The number of LANs included in the relay communication system may increase or decrease. Resources shared by the relay communication system may be updated. However, the relay communication system can update the relay group information and the shared resource information in response to these changes. And the relay communication system can construct | assemble a network with an expandability and flexibility corresponding to these changes.

JP 2008-129991 A

  In the relay communication system disclosed in Patent Document 1, a client terminal connected to one LAN performs communication with a client terminal connected to another LAN as follows.

  As the first section, communication starts between the client terminal connected to one LAN and the relay server. As an intermediate section, communication is relayed between relay servers connected to one LAN and another LAN. As the last section, communication ends between the relay server and the client terminal connected to another LAN.

  Communication in the first and last section is communication within the LAN. For this reason, IPv4 (Internet Protocol version 4) communication using a private IP (Internet Protocol) address is often adopted. Non-encrypted communication is often employed.

  Communication in the middle section is communication within the WAN. Therefore, IPv6 (Internet Protocol version 6) communication that does not deplete IP addresses may be employed. In addition, encryption communication may be employed.

  When the communication method in each section is unified, flexible operation as described above cannot be achieved. When the communication method in each section is an independent method, flexible operation can be achieved as described above, but means for facilitating flexible operation is not disclosed.

  In view of the above problems, the present invention is a relay communication system that enables a client terminal connected to a remote LAN to communicate over a WAN. The purpose is to provide a means for facilitating certain operations.

  In order to solve the above problem, the invention according to claim 1 is a relay server that can communicate with the first relay server connected to the first network and functions as the second relay server connected to the second network. A relay group information creating unit that creates relay group information indicating that the first relay server and the second relay server constitute a relay group, and a first relay server activation that indicates an activation state of the first relay server First client terminal registration related to the first client terminal registered in the first relay server including information and a connection state between the first relay server and the first client terminal connected to the first network Information, first relay server information created by the first relay server, and a second relay server start indicating an activation state of the second relay server Second client terminal registration related to the second client terminal registered in the second relay server including information and a connection state between the second relay server and the second client terminal connected to the second network Information, and the relay server information including the second relay server information created by the second relay server, and the relay group information between the first relay server and the second relay server. A sharing unit between relay servers to be shared; a sharing unit between client terminals that shares the relay group information and the relay server information between the second relay server and the second client terminal; the relay group information; A communication execution unit that executes communication relayed by the second relay server to a destination selected based on the relay server information. The communication unit can set different communication schemes for communication destined for a terminal in the second network and communication destined for a terminal in the first network. A transfer destination determination unit that determines a transfer destination by collating specified identification information with the identification information described in the relay group information and the relay server information, and the transfer destination based on the transfer destination And a communication method determination unit for determining a communication method for.

  According to a second aspect of the present invention, in the relay server according to the first aspect, the communication method determining unit generates an address setting information for associating the transfer destination with an address setting method for the transfer destination. And an address setting method determining unit that determines an address setting method for the transfer destination based on the transfer destination and the address setting information.

  According to a third aspect of the present invention, in the relay server according to the first or second aspect, the communication method determining unit creates encrypted communication setting information that associates the transfer destination with an encrypted communication method for the transfer destination. An encryption communication setting information generation unit; and an encryption communication setting method determination unit that determines an encryption communication setting method for the transfer destination based on the transfer destination and the encryption communication setting information.

  The invention according to claim 4 is a relay communication comprising a first network, a second network, a first relay server connected to the first network, and a second relay server connected to the second network. The first relay server and the second relay server are relay systems that create relay group information indicating that the first relay server and the second relay server constitute a relay group. The first relay server includes: first relay server activation information indicating an activation state of the first relay server; and a first client terminal connected to the first relay server and the first network. First client terminal registration information relating to the first client terminal registered in the first relay server including a connection state between the first relay server and the first relay server A first relay server information creating unit for creating a report, wherein the second relay server includes second relay server activation information indicating an activation state of the second relay server, the second relay server, and the second network. Second relay server information including second client terminal registration information related to the second client terminal registered in the second relay server, including a connection state with the second client terminal connected to A second relay server information creating unit, wherein the first relay server and the second relay server include the relay server information including the first relay server information and the second relay server information, and the relay group An inter-relay server sharing unit that shares information between the first relay server and the second relay server, the first relay server including the relay group information and the medium A first inter-client-terminal sharing unit that shares server information between the first relay server and the first client terminal, wherein the second relay server includes the relay group information and the relay server information. A second inter-client-terminal sharing unit that is shared between the second relay server and the second client terminal, wherein the first relay server is selected based on the relay group information and the relay server information A communication execution unit that executes communication relayed by the first relay server to the destination, the communication execution unit configured to communicate with a terminal in the second network and a terminal in the first network. Different communication methods can be set, and the communication execution unit can identify the identification information designated as the destination, the relay group information, and the A transfer destination determination unit that determines a transfer destination by collating the identification information described in the relay server information; a communication method determination unit that determines a communication method for the transfer destination based on the transfer destination; It is characterized by including.

  According to a fifth aspect of the present invention, in the relay communication system according to the fourth aspect, the communication method determination unit generates address setting information for associating the transfer destination with an address setting method for the transfer destination. And an address setting method determination unit that determines an address setting method for the transfer destination based on the transfer destination and the address setting information.

  According to a sixth aspect of the present invention, in the relay communication system according to the fourth or fifth aspect, the communication method determination unit creates encrypted communication setting information that associates the transfer destination with an encrypted communication method for the transfer destination. And an encryption communication setting information determination unit that determines an encryption communication setting method for the transfer destination based on the transfer destination and the encryption communication setting information.

  The relay communication system includes a first network and a second network. The first network includes a first relay server and a first client terminal. The second network includes a second relay server and a second client terminal. The first relay server and the second relay server relay communication between the first client terminal and the second client terminal.

  The first (second) relay server creates relay group information, first (second) relay server information, and client terminal information. The relay group information is information indicating that the first relay server and the second relay server constitute a relay group. The first (second) relay server information is information indicating a first (second) client terminal that can communicate with the first (second) relay server. The client terminal information is information indicating a connection environment of the first (second) client terminal in the first (second) network.

  The first (second) relay server can share the first relay server information and the second relay server information between the first relay server and the second relay server by referring to the relay group information. The first (second) relay server refers to each client terminal information so that the relay group information and the relay server information can be obtained between the first (second) relay server and the first (second) client terminal. Can share.

  The first (second) relay server executes communication relayed by the first (second) relay server to the destination selected based on the relay group information and the relay server information. The first (second) relay server determines the transfer destination by comparing the identification information designated as the destination with the identification information described in the relay group information and the relay server information. The first (second) relay server determines a communication method for the transfer destination, such as an address setting method and an encryption communication setting method, based on the transfer destination. The relay communication system can easily achieve flexible operation in which the communication method in each section is an independent method.

{Overall configuration of relay communication system}
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating an overall configuration of a relay communication system. The relay communication system includes LANs 1 and 2 and WAN3. LANs 1 and 2 are small-scale networks constructed remotely. The WAN 3 is a large-scale network such as the Internet.

  The LAN 1 includes a client terminal 11 and a relay server 12. The LAN 2 includes a client terminal 21 and a relay server 22. The WAN 3 includes a SIP (Session Initiation Protocol) server 31.

  The client terminals 11 and 21 are personal computers or the like. The relay servers 12 and 22 relay communication between the client terminals 11 and 21. The SIP server 31 relays communication between the relay servers 12 and 22.

  In the present embodiment, SIP is used as a communication protocol between the relay servers 12 and 22, but a protocol other than SIP may be used. When a protocol other than SIP is used, communication between the relay servers 12 and 22 may be directly executed.

  As communication between the client terminal 11 and the relay server 12, IPv4 communication and non-encrypted communication are adopted. As communication between the relay server 12 and the relay server 22, IPv6 communication and encryption communication are adopted. As communication between the client terminal 21 and the relay server 22, IPv4 communication and non-encrypted communication are adopted.

{Components of relay server}
FIG. 2 is a diagram showing components of the relay server 12 (22). The relay server 12 (22) includes an interface unit 121 (221), a control unit 122 (222), and a database storage unit 123 (223). A code without parentheses indicates a code in the relay server 12. Reference numerals with parentheses indicate reference numerals in the relay server 22.

  The interface unit 121 (221) performs communication with the client terminal 11 (21) connected to the LAN 1 (2) using a private IP address in IPv4 communication. The interface unit 121 (221) performs communication with the SIP server 31 connected to the WAN 3 by using an IP address in IPv6 communication.

  The control unit 122 (222) executes control for relaying communication between the client terminals 11 and 21. The control unit 122 (222) creates or updates the relay group information, relay server information, and client terminal information stored in the database storage unit 123 (223). The control unit 122 (222) creates network setting information and encrypted communication setting information stored in the database storage unit 123 (223).

  The database storage unit 123 (223) includes a relay group information storage unit 124 (224), a relay server information storage unit 125 (225), a client terminal information storage unit 126 (226), a network setting information storage unit 127 (227), an encryption It is comprised from the communication setting information storage part 128 (228). The above information will be described below.

{Specific example of relay group information}
FIG. 3 is a diagram illustrating the relay group information 40 as a specific example of the relay group information. The relay group information is information indicating an outline of the relay server that constitutes the relay communication system.

  The relay group information 40 includes upper information 401 and lower information 402. The upper information 401 includes relay group identification information 403. The lower information 402 includes relay server identification information 404.

  The upper information 401 is information regarding the relay group at the upper level. The relay group identification information 403 is information for identifying the relay group shown in FIG. “Lastmod” indicates the latest update time of the relay group information. “Name” indicates the name of the relay group.

  The lower information 402 is information about the relay server at the lower level. The relay server identification information 404 is information for identifying the relay server.

  The relay group information 40 is stored in the relay group information storage units 124 and 224. That is, the relay group information 40 is shared by the relay servers 12 and 22. Further, the relay group information 40 is shared by the relay servers 12 and 22 and the client terminals 11 and 21.

{Specific example of relay server information}
FIG. 4 is a diagram illustrating the relay server information 50 as a specific example of the relay server information. The relay server information is information that indicates details of the relay server that constitutes the relay communication system, and is an information that indicates an outline of the client terminal that constitutes the relay communication system.

  The relay server information 50 includes upper information 501-1 and 501-2 and lower information 502-1 and 502-2. The upper information 501-1 and 501-2 include relay server identification information 503-1 and 503-2, and relay server activation information 504-1 and 504-2, respectively. The lower information 502-1 and 502-2 indicate relay group identification information 505-1 and 505-2, client terminal identification information 506-1 and 506-2, and whether the client terminal is logged in to the relay server, respectively. Client terminal site information 507-1 and 507-2 are included.

  The upper information 501-1 and 501-2 are information on the relay server at the upper level. The relay server identification information 503-1 and 503-2 are information for identifying the relay server. “Name” indicates the name of the relay server. The relay server activation information 504-1 and 504-2 are information about whether the relay server is activated.

  The lower information 502-1 and 502-2 are information about the lower client terminals. “Div” indicates a department name of the client terminal. The relay group identification information 505-1 and 505-2 are information for identifying the relay group shown in FIG. The client terminal identification information 506-1 and 506-2 are information for identifying the client terminal. “Name” indicates the name of the client terminal. Client terminal site information 507-1 and 507-2 indicate identification information of the relay server to which the client terminal is logged on.

  The relay server information 50 is stored in the relay server information storage units 125 and 225. That is, the relay server information 50 is shared by the relay servers 12 and 22. Further, the relay server information 50 is shared by the relay servers 12 and 22 and the client terminals 11 and 21.

  When the relay server is activated, the relay server activation information 504-1 and 504-2 are “active”. When the relay server is not activated, the relay server activation information 504-1 and 504-2 are blank. Thereby, information about whether the relay server is activated is shared as the whole relay communication system.

  When the client terminal is logged on to the relay server, client terminal site information 507-1 and 507-2 are described. When the client terminal is not logged on to the relay server, the client terminal site information 507-1 and 507-2 are not described. As a result, information about whether the client terminal is logged on to the relay server is shared as the entire relay communication system.

{Specific examples of client terminal information}
FIG. 5 is a diagram showing client terminal information 60 and 70 as specific examples of the client terminal information. The client terminal information is information indicating details of the client terminals that constitute the relay communication system.

  The client terminal information 60 and 70 are relay group identification information 601 and 701, client terminal address information 602 and 702, client terminal expiration information 603 and 703, client terminal identification information 604 and 704, client terminal port information 605 and 705, respectively. including.

  “Div” indicates a department name of the client terminal. The relay group identification information 601 and 701 is information for identifying the relay group shown in FIG. The client terminal address information 602 and 702 indicates the IP address of the client terminal. The client terminal expiration date information 603 and 703 indicates the registration expiration date of the client terminal. The client terminal identification information 604 and 704 is information for identifying the client terminal. “Name” indicates the name of the client terminal. “Pass” indicates a password of the client terminal. The client terminal port information 605 and 705 indicates the port number of the client terminal.

  The client terminal information 60 is stored only in the client terminal information storage unit 126, and the client terminal information 70 is stored only in the client terminal information storage unit 226. That is, the client terminal information 60 is held only by the relay server 12, and the client terminal information 70 is held only by the relay server 22.

{Network setting information}
FIG. 6 is a diagram showing the network setting information 81 stored in the network setting information storage unit 127 by the relay server 12. The WAN-side setting information 811 indicates that IPv6 communication is adopted between the relay server 12 and the relay server 22 as shown in FIG. The LAN-side setting information 812 indicates that IPv4 communication is adopted between the client terminal 11 and the relay server 12, as shown in FIG.

  The WAN side setting information 811 will be described. As an IP address in the IPv6 communication of the relay server 12, “2001: 222: 1002: 2000 :: 5” is set. “5060” is set as the signaling port, “5062” is set as the secure signaling port, and “5070” is set as the session port.

  The LAN side setting information 812 will be described. As the private IP address in the IPv4 communication of the relay server 12, “192.168.10.1” is set. With the adoption of IPv4 communication, “255.255.255.0” as a subnet mask, “192.168.10.3” as a DNS (Domain Name Server) address, and “192.255” as a gateway address. 168.10.3 "is set. “5060” is set as the signaling port, “5062” is set as the secure signaling port, and “5070” is set as the session port.

  FIG. 7 is a diagram showing the network setting information 82 stored in the network setting information storage unit 227 by the relay server 22. The WAN-side setting information 821 indicates that IPv6 communication is adopted between the relay server 12 and the relay server 22 as shown in FIG. The LAN side setting information 822 indicates that IPv4 communication is adopted between the client terminal 21 and the relay server 22 as shown in FIG.

  The WAN side setting information 821 will be described. As the IP address in the IPv6 communication of the relay server 22, “2001: 222: 1002: 2000 :: 6” is set. “5060” is set as the signaling port, “5062” is set as the secure signaling port, and “5070” is set as the session port.

  The LAN side setting information 822 will be described. “192.168.1.1” is set as a private IP address in the IPv4 communication of the relay server 22. With the adoption of IPv4 communication, “255.255.255.0” as a subnet mask, “192.168.1.2” as a DNS (Domain Name Server) address, and “192. 168.1.2 ”is set. “5060” is set as the signaling port, “5062” is set as the secure signaling port, and “5070” is set as the session port.

  When the transmission side transmits data to the reception side over WAN 3, the identification information on the reception side is specified as the destination without specifying the IP address on the reception side as the destination.

  The relay servers 12 and 22 confirm the receiving side identification information specified as the destination. Then, the relay servers 12 and 22 determine the relay server to which data is transferred by referring to the relay group information, relay server information, and client terminal information. And the relay servers 12 and 22 employ | adopt IPv4 communication or IPv6 communication as a communication system corresponding to the relay server which transfers data by referring network setting information.

{Encryption communication setting information}
FIG. 8 is a diagram showing the encrypted communication setting information 91 stored in the encrypted communication setting information storage unit 128 by the relay server 12. The WAN side setting information 911 indicates that encryption communication is adopted between the relay server 12 and the relay server 22 as shown in FIG. The LAN side setting information 912 indicates that non-encrypted communication is adopted between the client terminal 11 and the relay server 12, as shown in FIG.

  The WAN side setting information 911 will be described. “ON” is set as information indicating that encrypted communication is employed. With the adoption of encryption communication, “1001: 118: 0f02: 1000 :: 165” as the authentication server, “4347384957YHD” as the authentication ID, “orKgHD5e3344A” as the authentication password, and “relay−” as the user name “server-1@abc.net” is set with “5060” as the authentication server signaling port and “5062” as the authentication server secure signaling port.

  The LAN side setting information 912 will be described. “OFF” is set as information indicating that non-encrypted communication is employed. Along with the adoption of non-encrypted communication, setting items for the authentication server, authentication ID, authentication password, user name, authentication server signaling port, and authentication server secure signaling port are blank.

  FIG. 9 is a diagram showing encrypted communication setting information 92 stored in the encrypted communication setting information storage unit 228 by the relay server 22. The WAN-side setting information 921 indicates that encryption communication is adopted between the relay server 12 and the relay server 22 as shown in FIG. The LAN side setting information 922 indicates that non-encrypted communication is adopted between the client terminal 21 and the relay server 22 as shown in FIG.

  The WAN side setting information 921 will be described. “ON” is set as information indicating that encrypted communication is employed. With the adoption of encryption communication, “1001: 118: 0f02: 1000 :: 165” as the authentication server, “43474834957XYZ” as the authentication ID, “orKgHD5e1234B” as the authentication password, and “relay−” as the user name In “server-2@abc.net”, “5060” is set as the authentication server signaling port in TCP communication, and “5062” is set as the authentication server secure signaling port.

  The LAN side setting information 922 will be described. “OFF” is set as information indicating that non-encrypted communication is employed. Along with the adoption of non-encrypted communication, setting items for the authentication server, authentication ID, authentication password, user name, authentication server signaling port, and authentication server secure signaling port are blank.

  When the transmission side transmits data to the reception side over WAN 3, the identification information on the reception side is specified as the destination without specifying the IP address on the reception side as the destination.

  The relay servers 12 and 22 confirm the receiving side identification information specified as the destination. Then, the relay servers 12 and 22 determine the other party to which the data is transferred by referring to the relay group information, the relay server information, and the client terminal information. Furthermore, the relay servers 12 and 22 employ encrypted communication or non-encrypted communication as a communication method for the other party to which data is transferred by referring to the encrypted communication setting information.

{Information sharing flow}
FIG. 10 is a diagram illustrating a flow of processing in which relay group information and relay server information are shared. The relay servers 12 and 22 participate in the relay communication system. The user of the client terminal 11 logs on to the relay server 12, and the user of the client terminal 21 logs on to the relay server 22.

[Processing flow from step S1 to step S2]
The administrator of the relay server 12 and the administrator of the relay server 22 make a contract for building a group of relay communication systems between the LANs 1 and 2.

  The administrator of the relay server 12 and the administrator of the relay server 22 determine the description contents of the WAN side setting information 811 and the WAN side setting information 821, respectively. The control unit 122 and the control unit 222 create WAN-side setting information 811 and WAN-side setting information 821, respectively, and store them in the network setting information storage unit 127 and the network setting information storage unit 227, respectively.

  The administrator of the relay server 12 and the administrator of the relay server 22 determine the description contents of the WAN side setting information 911 and the WAN side setting information 921, respectively. The control unit 122 and the control unit 222 create WAN side setting information 911 and WAN side setting information 921, respectively, and store them in the encrypted communication setting information storage unit 128 and the encrypted communication setting information storage unit 228.

  The administrator of the relay server 12 creates an account for the user of the client terminal 11 (step S1: CreateAccount ()). The control unit 122 creates relay server information 51-1 and stores it in the relay server information storage unit 125.

  The administrator of the relay server 12 determines the description contents of the LAN side setting information 812 and the LAN side setting information 912. The control unit 122 creates the LAN side setting information 812 and the LAN side setting information 912 and stores them in the network setting information storage unit 127 and the encrypted communication setting information storage unit 128, respectively.

  The administrator of the relay server 22 creates an account for the user of the client terminal 21 (Step S2: CreateAccount ()). The control unit 222 creates relay server information 51-2 and stores it in the relay server information storage unit 225.

  The administrator of the relay server 22 determines the description contents of the LAN side setting information 822 and the LAN side setting information 922. The control unit 222 creates the LAN side setting information 822 and the LAN side setting information 922 and stores them in the network setting information storage unit 227 and the encrypted communication setting information storage unit 228, respectively.

  Through the above processing flow, the relay server 12 holds the relay server information 51-1, the network setting information 81, and the encrypted communication setting information 91. The relay server 22 has relay server information 51-2, network setting information 82, and encrypted communication setting information 92.

  The first frame in FIG. 11 shows the relay server information 51-1. The upper information 511-1 is information about the relay server 12 at the upper level. As the relay server identification information 513-1, “relay-server-1@abc.net” is set. “RELAY SERVER 1” is set as “name”. As the relay server activation information 514-1, “active” is set. That is, the relay server 12 is activated.

  The lower information 512-1 is information about the client terminal 11 at the lower level. “Software” is set as “div”. As the relay group identification information 515-1, “2007040402133100@relay-server-1.abc.net” is set. As client terminal identification information 516-1, “client-1@relay-server-1.abc.net” is set. “CLIENT 1” is set as “name”. The client terminal site information 517-1 is blank. That is, the user of the client terminal 11 is not logged on to the relay server 12.

  The second frame in FIG. 11 shows the relay server information 51-2. The upper information 511-2 is information about the relay server 22 at the upper level. As the relay server identification information 513-2, “relay-server-2@abc.net” is set. “RELAY SERVER 2” is set as “name”. “Active” is set as the relay server activation information 514-2. That is, the relay server 22 is activated.

  The lower information 512-2 is information about the client terminal 21 that is a lower level. “Software” is set as “div”. As the relay group identification information 515-2, “2007040402133100@relay-server-1.abc.net” is set. As client terminal identification information 516-2, “client-2@relay-server-2.abc.net” is set. “CLIENT 2” is set as “name”. The client terminal site information 517-2 is blank. That is, the user of the client terminal 21 is not logged on to the relay server 22.

[Processing flow from step S3 to step S4]
In the following description, communication between the relay servers 12 and 22 is relayed by the SIP server 31. A method in which the relay server 12 (22) performs communication with the relay server 22 (12) via the SIP server 31 will be described.

  The relay server 12 (22) transmits, for example, data in which the account of the relay server 22 (12) is designated as a communication destination to the SIP server 31. The SIP server 31 associates the accounts of the relay servers 12 and 22 with the IP addresses in the IPv6 communication of the relay servers 12 and 22, respectively. The SIP server 31 acquires the IP address in the IPv6 communication of the relay server 22 (12) based on the account of the relay server 22 (12). The SIP server 31 transmits, for example, data in which the IP address in the IPv6 communication of the relay server 22 (12) is designated as the communication destination to the relay server 22 (12).

  The relay server 12 requests the relay server 22 to construct a group of the relay communication system (step S3: SetGroup ()). The control unit 122 creates the relay group information 42 and stores it in the relay group information storage unit 124. The control unit 222 creates the relay group information 42 and stores it in the relay group information storage unit 224.

  The relay server 12 requests the relay server 22 to exchange relay server information (step S4: exchange (db)). The relay server 12 transmits a copy of the relay server information 51-1 to the relay server 22. The relay server 22 transmits a copy of the relay server information 51-2 to the relay server 12.

  The control unit 122 creates the relay server information 52 by duplicating the relay server information 51-2 and combining the relay server information 51-1, and stores the relay server information 52 in the relay server information storage unit 125. The control unit 222 creates the relay server information 52 by combining the relay server information 51-1 and the relay server information 51-2, and stores the relay server information 52 in the relay server information storage unit 225.

  The control unit 122 creates client terminal information 62 and stores it in the client terminal information storage unit 126. The control unit 222 creates client terminal information 72 and stores it in the client terminal information storage unit 226. The creation process and storage process of the client terminal information 62 are executed in step S1, and the creation process and storage process of the client terminal information 72 are executed in step S2.

  Through the above processing flow, the relay server 12 holds the relay group information 42, the relay server information 52, and the client terminal information 62. The relay server 22 has relay group information 42, relay server information 52, and client terminal information 72. The relay group information 42 and the relay server information 52 are shared by the relay servers 12 and 22.

  The first frame in FIG. 12 shows the relay group information 42. The upper information 421 is information about the relay group at the upper level. As the relay group identification information 423, “20070402133100@relay-server-1.abc.net” is set. As “lastmod”, “20070402133100” is set. “GROUP 1” is set as “name”.

  The lower information 422 is information about the relay servers 12 and 22 that are lower. As relay server identification information 424, “relay-server-1@abc.net” and “relay-server-2@abc.net” are set.

  The second frame in FIG. 12 shows the relay server information 52. The upper information 521-1 and 521-2 are the same as the upper information 511-1 and 511-2 in FIG. 11, respectively. The lower information 522-1 and 522-2 are the same as the lower information 512-1 and 512-2 in FIG. 11, respectively.

  The third frame in FIG. 12 shows client terminal information 62. “Software” is set as “div”. As the relay group identification information 621, “2007040402133100@relay-server-1.abc.net” is set. As client terminal identification information 624, “client-1@relay-server-1.abc.net” is set. “CLIENT 1” is set as “name”. “Client-1” is set as “pass”.

  The client terminal address information 622 is blank. “0” is set as the client terminal expiration date information 623. The client terminal port information 625 is blank. That is, the user of the client terminal 11 is not logged on to the relay server 12.

  The fourth frame in FIG. 12 shows client terminal information 72. “Software” is set as “div”. As the relay group identification information 721, “20070402133100@relay-server-1.abc.net” is set. As client terminal identification information 724, “client-2@relay-server-2.abc.net” is set. “CLIENT 2” is set as “name”. “Client-2” is set as “pass”.

  The client terminal address information 722 is blank. “0” is set as the client terminal expiration date information 723. The client terminal port information 725 is blank. That is, the user of the client terminal 21 is not logged on to the relay server 22.

[Processing flow from step S5 to step S7]
The user of the client terminal 11 inputs “client-1@relay-server-1.abc.net” as the identification information of the client terminal 11 and inputs “client-1” as the password of the client terminal 11. . The user of the client terminal 11 logs on to the relay server 12 (step S5: REGISTER (ID, PASS)). The control unit 122 performs authentication of the user of the client terminal 11 by referring to the client terminal information 62.

  The control unit 122 accepts logon of the user of the client terminal 11. The control unit 122 creates the relay server information 53 by updating the relay server information 52 and stores it in the relay server information storage unit 125. The control unit 122 creates the client terminal information 63 by updating the client terminal information 62 and stores the client terminal information 63 in the client terminal information storage unit 126. The control unit 122 does not update the relay group information 42.

  The client terminal 11 requests the relay server 12 to provide relay group information and relay server information (step S6: get ()). The relay server 12 transmits a copy of the relay group information 42 and the relay server information 53 to the client terminal 11. The client terminal 11 stores relay group information 42 and relay server information 53.

  The control unit 122 refers to the relay group information 42 and the relay server information 53 to determine a relay server to be notified that the relay server information 52 has been updated to the relay server information 53. The control unit 122 determines the relay server 22 whose relay server activation information 534-2 of the relay server information 53 is “active” as a relay server to be notified.

  The relay server 12 notifies the relay server 22 that the relay server information 52 has been updated to the relay server information 53 (step 7: NOTIFY ()). The control unit 222 updates the relay server information 52 to create the relay server information 53 and stores it in the relay server information storage unit 225.

  The control unit 222 refers to the client terminal information 72 to determine a client terminal to be notified that the relay server information 52 has been updated to the relay server information 53. The control unit 222 does not determine the client terminal 21 in which the client terminal address information 722 of the client terminal information 72 is blank and the client terminal port information 725 of the client terminal information 72 is blank as a client terminal to be notified. .

  Through the above processing flow, the relay server 12 holds the relay group information 42, the relay server information 53, and the client terminal information 63. The relay server 22 has relay group information 42, relay server information 53, and client terminal information 72. The client terminal 11 has relay group information 42 and relay server information 53. The relay group information 42 and the relay server information 53 are shared by the relay servers 12 and 22 and the client terminal 11.

  The first frame in FIG. 13 shows the relay group information 42. In the process flow from step S5 to step S7, the relay group information 42 is not updated because a new relay server has not participated in the relay communication system.

  The second frame in FIG. 13 shows relay server information 53. The updated part is indicated by the underlined part. The user of the client terminal 11 is logged on to the relay server 12. Therefore, the client terminal site information 537-1 of the lower information 532-1 is fixed to “relay-server-1@abc.net”.

  The third frame in FIG. 13 shows client terminal information 63. The updated part is indicated by the underlined part. The user of the client terminal 11 is logged on to the relay server 12. Therefore, the client terminal address information 632 is fixed to “192.168.10.2”. Further, the client terminal expiration date information 633 is determined to be “1213935960484”. Further, the client terminal port information 635 is fixed to “5070”.

  The fourth frame in FIG. 13 shows client terminal information 72. In the processing flow from step S5 to step S7, since the user of the client terminal 21 is not logged on to the relay server 22, the client terminal information 72 is not updated.

[Flow of processing from step S8 to step S11]
The user of the client terminal 21 inputs “client-2@relay-server-2.abc.net” as identification information of the client terminal 21, and inputs “client-2” as the password of the client terminal 21. . The user of the client terminal 21 logs on to the relay server 22 (step S8: REGISTER (ID, PASS)). The control unit 222 performs authentication of the user of the client terminal 21 by referring to the client terminal information 72.

  The control unit 222 accepts logon of the user of the client terminal 21. The control unit 222 updates the relay server information 53 to create the relay server information 54 and stores it in the relay server information storage unit 225. The control unit 222 creates the client terminal information 74 by updating the client terminal information 72 and stores it in the client terminal information storage unit 226. The control unit 222 does not update the relay group information 42.

  The client terminal 21 requests the relay server 22 to provide relay group information and relay server information (step S9: get ()). The relay server 22 transmits a copy of the relay group information 42 and the relay server information 54 to the client terminal 21. The client terminal 21 stores relay group information 42 and relay server information 54.

  The control unit 222 refers to the relay group information 42 and the relay server information 54 to determine a relay server to be notified that the relay server information 53 has been updated to the relay server information 54. The control unit 222 determines the relay server 12 whose relay server activation information 544-1 of the relay server information 54 is “active” as a relay server to be notified.

  The relay server 22 notifies the relay server 12 that the relay server information 53 has been updated to the relay server information 54 (step 10: NOTIFY ()). The control unit 122 creates the relay server information 54 by updating the relay server information 53 and stores it in the relay server information storage unit 125.

  The control unit 122 refers to the client terminal information 63 to determine a client terminal to be notified that the relay server information 53 has been updated to the relay server information 54. The control unit 122 determines the client terminal 11 in which the client terminal address information 632 of the client terminal information 63 is determined and the client terminal port information 635 of the client terminal information 63 is determined as a client terminal to be notified.

  The relay server 12 notifies the client terminal 11 that the relay server information 53 has been updated to the relay server information 54 (step 11: NOTIFY ()). The client terminal 11 creates the relay server information 54 by updating the relay server information 53 and stores the relay server information 54.

  Through the above processing flow, the relay server 12 has the relay group information 42, the relay server information 54, and the client terminal information 63. The relay server 22 has relay group information 42, relay server information 54, and client terminal information 74. The client terminal 11 has relay group information 42 and relay server information 54. The client terminal 21 has relay group information 42 and relay server information 54. The relay group information 42 and the relay server information 54 are shared by the relay servers 12 and 22 and the client terminals 11 and 21.

  The first frame in FIG. 14 shows the relay group information 42. In the processing flow from step S8 to step S11, the relay group information 42 is not updated because a new relay server does not participate in the relay communication system.

  The second frame in FIG. 14 shows relay server information 54. The updated part is indicated by the underlined part. The user of the client terminal 21 is logged on to the relay server 22. Therefore, the client terminal site information 547-2 of the lower information 542-2 is fixed to “relay-server-2@abc.net”.

  The third frame in FIG. 14 shows client terminal information 63. In the processing flow from step S8 to step S11, since the user of the client terminal 11 has not logged off from the relay server 12, the client terminal information 63 is not updated.

  The fourth frame in FIG. 14 shows client terminal information 74. The updated part is indicated by the underlined part. The user of the client terminal 21 is logged on to the relay server 22. Therefore, the client terminal address information 742 is fixed at “192.168.1.10”. Further, the client terminal expiration date information 743 is fixed to “1213935978484”. Further, the client terminal port information 745 is fixed to “5070”.

{Summary of information sharing}
In a relay communication system, the increase / decrease state and connection state of LANs and client terminals may change. Therefore, when one relay server recognizes the state change, it immediately updates the relay group information, the relay server information, and the client terminal information.

  Then, the one relay server immediately notifies the other relay servers described in the relay group information and the relay server information that the relay group information and the relay server information are updated. Further, the one relay server immediately notifies the client terminal described in the client terminal information that the relay group information and the relay server information are updated.

  However, if one relay server determines that another relay server is not connected even if the other relay server is described in the relay group information and relay server information, it immediately notifies the other relay server. Never do. Furthermore, even if the client terminal is described in the client terminal information, the one relay server does not immediately notify the client terminal when it is determined that the client terminal is not connected.

  Thereby, the information about the increase / decrease state and connection state of the LAN and the client terminal is shared in real time as the entire relay communication system.

{Flow of data transmission / reception}
15 to 17 are diagrams showing a flow of data transmission / reception after information sharing. After the information sharing, the relay group information 42, the relay server information 54, and the client terminal information 63 and 74 shown in FIG. 14 are stored. The user of the client terminal 11 is logged on to the relay server 12. The user of the client terminal 21 is logged on to the relay server 22.

  In the following description, “destination” and “transfer destination” are defined as follows. “Destination” indicates a final transmission destination of data transmission. The “transfer destination” indicates a transmission destination of data transmission in a single section of the LANs 1, 2, and WAN3 when data transmission over a plurality of sections of the LANs 1, 2, and WAN3 is executed.

[Processing flow from step S12 to step S15]
FIG. 15 shows the flow of processing for transmitting and receiving data in units of blocks. The user of the client terminal 11 confirms the relay group to which the client terminal 11 belongs. Specifically, the user of the client terminal 11 displays the relay group information 42 on the display screen of the client terminal 11 (getGroup ()). In the relay group information 42, identification information “relay-server-1@abc.net” and “relay-server-2@abc.net” of the relay servers 12 and 22 are set. The user of the client terminal 11 confirms that the client terminal 11 belongs to a relay group configured by the relay servers 12 and 22.

  The user of the client terminal 11 displays the relay server information 54 corresponding to the relay group information 42 on the display screen of the client terminal 11 (getServer ()). The user of the client terminal 11 refers to the relay server information 54 and confirms the relay server that configures the relay group and the client terminal that is positioned below the relay server.

  The user of the client terminal 11 refers to the relay server information 54 and confirms that data transmission / reception with the relay server 22 is possible. The user of the client terminal 11 confirms that the relay server activation information 544-1 of the relay server information 54 is set to “active” for the relay server 12. That is, it is confirmed that the relay server 12 is activated.

  The user of the client terminal 11 confirms that the relay server activation information 544-2 of the relay server information 54 is set to “active” for the relay server 22. That is, it is confirmed that the relay server 22 is activated.

  The user of the client terminal 11 confirms that data can be transmitted to the relay server 22 via the relay server 12. The user of the client terminal 11 determines to transmit block unit data to the relay server 22.

  In communication between the client terminal 11 and the relay server 12 (dialog (1)), the client terminal 11 transmits block unit data destined for the relay server 22 to the relay server 12 (step S12: data (from: client-1, to: relay-server-2)). The relay server 12 receives data in block units from the client terminal 11 in the dialog (1).

  The client terminal 11 does not specify the IP address of the relay server 22 in the IPv6 communication as the destination. The client terminal 11 uses the identification information of the relay server 22 as the destination by referring to the relay server identification information 424 of the relay group information 42 or by referring to the relay server identification information 543-2 of the relay server information 54. specify.

  As determined between the user of the client terminal 11 and the administrator of the relay server 12, the client terminal 11 employs IPv4 communication and non-encrypted communication in the dialog (1). The client terminal 11 designates the private IP address of the relay server 12 in the IPv4 communication as the transfer destination of dialog (1).

  In the communication (dialog (2)) between the relay server 12 and the relay server 22, the relay server 12 transmits block unit data destined for the relay server 22 to the relay server 22 (step S13: data (from: client-1, to: relay-server-2)). The relay server 22 receives block unit data from the relay server 12 in the dialog (2).

  The relay server 12 confirms the identification information of the relay server 22 as a destination. The relay server 12 refers to the relay server identification information 424 of the relay group information 42, or refers to the relay server identification information 543-2 of the relay server information 54, so that the destination is not on the LAN1 side and separates the WAN3. Confirm that it is on the LAN2 side.

  The relay server 12 employs IPv6 communication in the dialog (2) by referring to the WAN side setting information 811 in the network setting information 81. The relay server 12 employs encryption communication (for example, communication using a protocol such as IPsec (Security Architecture for Internet Protocol)) in the dialog (2) by referring to the WAN side setting information 911 in the encryption communication setting information 91. To do. The relay server 12 performs communication via the SIP server 31 as described in steps S3 and S4.

  In the dialog (2), the relay server 22 transmits a response indicating that the block unit data has been received to the relay server 12 (step S14: response (from: relay-server-2, to: client). -1)). The relay server 12 receives a response indicating that block-unit data has been received from the relay server 22 in the dialog (2).

  The relay server 22 does not specify the private IP address of the client terminal 11 in the IPv4 communication as a reply destination. The relay server 22 designates the identification information of the client terminal 11 designated as the transmission source as a reply destination. The relay server 22 refers to the client terminal identification information 546-1 of the relay server information 54 to confirm that the reply destination is not on the LAN2 side but on the LAN1 side across the WAN3.

  The relay server 22 employs IPv6 communication in the dialog (2) by referring to the WAN side setting information 821 in the network setting information 82. The relay server 22 refers to the WAN-side setting information 921 in the encrypted communication setting information 92, and adopts encrypted communication in the dialog (2). The relay server 22 performs communication via the SIP server 31 as described in steps S3 and S4.

  In the dialog (1), the relay server 12 transmits a response indicating that block-unit data has been received to the client terminal 11 (step S15: response (from: relay-server-2, to: client). -1)). The client terminal 11 receives a response indicating that block unit data has been received from the relay server 12 in the dialog (1).

  The relay server 12 confirms the identification information of the client terminal 11 as a reply destination. The relay server 12 refers to the client terminal identification information 546-1 of the relay server information 54, or refers to the client terminal identification information 634 of the client terminal information 63, so that the reply destination is separated from the LAN 2 side. Confirm that it is on the LAN1 side.

  The relay server 12 employs IPv4 communication in the dialog (1) by referring to the LAN side setting information 812 in the network setting information 81. The relay server 12 employs non-encrypted communication in the dialog (1) by referring to the LAN side setting information 912 in the encrypted communication setting information 91. The relay server 12 designates the private IP address of the client terminal 11 in the IPv4 communication as the transfer destination of dialog (1).

  The dialog (1) is communication between the client terminal 11 and the relay server 12. The dialog (2) is communication between the relay server 12 and the relay server 22. The relay server 12 correlates dialog (1) and dialog (2) in different sections adjacent to each other.

  When the relay server 12 receives data in the dialog (1), the relay server 12 creates information indicating that the dialog (1) and the dialog (2) are associated with each other, and then transmits the data in the dialog (2). It is indicated by “dialog (1): recv () == dialog (2): send ()” that dialog (1) and dialog (2) are associated with each other in data transmission / reception.

  When the relay server 12 receives the response in the dialog (2), the relay server 12 refers to information indicating that the dialog (1) and the dialog (2) are associated with each other, and then transmits the response in the dialog (1). It is indicated by “dialog (1): send () == dialog (2): recv ()” that dialog (1) and dialog (2) are associated with each other in the transmission / reception of the response.

[Flow of processing from step S16 to step S19]
FIG. 16 shows a flow of processing for establishing a connection before continuously transmitting / receiving data. The user of the client terminal 11 confirms the relay group to which the client terminal 11 belongs. Specifically, the user of the client terminal 11 displays the relay group information 42 on the display screen of the client terminal 11 (getGroup ()). In the relay group information 42, identification information “relay-server-1@abc.net” and “relay-server-2@abc.net” of the relay servers 12 and 22 are set. The user of the client terminal 11 confirms that the client terminal 11 belongs to a relay group configured by the relay servers 12 and 22.

  The user of the client terminal 11 displays the relay server information 54 corresponding to the relay group information 42 on the display screen of the client terminal 11 (getServer ()). The user of the client terminal 11 refers to the relay server information 54 and confirms the relay server that configures the relay group and the client terminal that is positioned below the relay server.

  The user of the client terminal 11 refers to the relay server information 54 and confirms that data transmission / reception with the client terminal 21 is possible. The user of the client terminal 11 confirms that the relay servers 12 and 22 are activated, similarly to the processing flow from step S12 to step S15.

  The user of the client terminal 11 confirms that the client terminal site information 547-2 of the relay server information 54 is set to “relay-server-2@abc.net” for the client terminal 21. That is, it is confirmed that the client terminal 21 is logged on to the relay server 22.

  The user of the client terminal 11 confirms that data can be transmitted to the client terminal 21 via the relay servers 12 and 22. The user of the client terminal 11 determines to continuously transmit data to the client terminal 21.

  In the communication (stream (1)) between the client terminal 11 and the relay server 12, the client terminal 11 transmits connection establishment request information to the relay server 12 (step S16: open (client-2, client-1)).

  The client terminal 11 does not designate the private IP address of the client terminal 21 in the IPv4 communication as the destination. The client terminal 11 designates the identification information of the client terminal 21 as a destination by referring to the client terminal identification information 546-2 of the relay server information 54.

  As determined between the user of the client terminal 11 and the administrator of the relay server 12, the client terminal 11 employs IPv4 communication and non-encrypted communication in stream (1). The client terminal 11 designates the private IP address of the relay server 12 in the IPv4 communication as the transfer destination of stream (1).

  The relay server 12 associates the stream (1), communication between the relay server 12 and the relay server 22 (stream (2)) (stream (1): open () == stream (2): open ()). . In the stream (2), the relay server 12 transmits connection establishment request information to the relay server 22 (step S16.1: open (client-2, client-1)).

  The relay server 12 confirms the identification information of the client terminal 21 as the destination. The relay server 12 refers to the client terminal identification information 546-2 of the relay server information 54 to confirm that the destination is not on the LAN1 side but on the LAN2 side across the WAN3.

  The relay server 12 employs IPv6 communication in the stream (2) by referring to the WAN side setting information 811 in the network setting information 81. The relay server 12 employs encryption communication in the stream (2) by referring to the WAN side setting information 911 in the encryption communication setting information 91. The relay server 12 performs communication via the SIP server 31 as described in steps S3 and S4.

  The relay server 22 associates the stream (2), the communication (stream (3)) between the relay server 22 and the client terminal 21 (stream (2): open () == stream (3): open ()). . The relay server 22 transmits connection establishment request information using the client terminal information 74 to the client terminal 21 in the stream (3) (step S16.1.1: open (client-2, client-1). )). That is, the connection establishment request information is transmitted to the client terminal 21 based on the client terminal address information 742 “192.168.1.10” and the client terminal port information 745 “5070” corresponding to the client terminal 21. .

  The relay server 22 confirms the identification information of the client terminal 21 as the destination. The relay server 22 refers to the client terminal identification information 546-2 of the relay server information 54, or refers to the client terminal identification information 744 of the client terminal information 74, so that the destination is set to the LAN1 side across the WAN3. Confirm that it is on the LAN2 side.

  The relay server 22 employs IPv4 communication in the stream (3) by referring to the LAN side setting information 822 in the network setting information 82. The relay server 22 employs non-encrypted communication in the stream (3) by referring to the LAN side setting information 922 in the encrypted communication setting information 92. The relay server 22 designates the private IP address of the client terminal 21 in the IPv4 communication as the transfer destination of stream (3).

  In stream (3), the client terminal 21 transmits connection establishment permission information to the relay server 22 (ack for step S16.1.1).

  The client terminal 21 does not specify the private IP address of the client terminal 11 in the IPv4 communication as a reply destination. The client terminal 21 designates the identification information of the client terminal 11 designated as the transmission source as a reply destination.

  As determined between the user of the client terminal 21 and the administrator of the relay server 22, the client terminal 21 employs IPv4 communication and non-encrypted communication in stream (3). The client terminal 21 designates the private IP address of the relay server 22 in the IPv4 communication as the transfer destination of the stream (3).

  The relay server 22 refers to the association between stream (2) and stream (3) (stream (2): ack () == stream (3): ack ()). The relay server 22 transmits permission information for connection establishment to the relay server 12 in stream (2) (ack for step S16.1).

  The relay server 22 confirms the identification information of the client terminal 11 as a reply destination. The relay server 22 refers to the client terminal identification information 546-1 of the relay server information 54 to confirm that the reply destination is not on the LAN2 side but on the LAN1 side across the WAN3.

  The relay server 22 employs IPv6 communication in the stream (2) by referring to the WAN side setting information 821 in the network setting information 82. The relay server 22 refers to the WAN-side setting information 921 in the encrypted communication setting information 92, and adopts encrypted communication in the stream (2). The relay server 22 performs communication via the SIP server 31 as described in steps S3 and S4.

  The relay server 12 refers to the association between stream (1) and stream (2) (stream (1): ack () == stream (2): ack ()). The relay server 12 transmits connection establishment permission information to the client terminal 11 in stream (1) (ack for step S16).

  The relay server 12 confirms the identification information of the client terminal 11 as a reply destination. The relay server 12 refers to the client terminal identification information 546-1 of the relay server information 54, or refers to the client terminal identification information 634 of the client terminal information 63, so that the reply destination is separated from the LAN 2 side. Confirm that it is on the LAN1 side.

  The relay server 12 employs IPv4 communication in the stream (1) by referring to the LAN side setting information 812 in the network setting information 81. The relay server 12 employs non-encrypted communication in the stream (1) by referring to the LAN side setting information 912 in the encrypted communication setting information 91. The relay server 12 specifies the private IP address of the client terminal 11 in the IPv4 communication as the transfer destination of the stream (1).

  The client terminal 11 establishes a connection (connection (1)) between the client terminal 11 and the relay server 12 to the relay server 12 (step S17: connection (1)). In establishing connection (1), the flow of processing in which IPv4 communication and non-encrypted communication are employed is the same as ack for step S16 and step S16.

  The relay server 12 establishes a connection (connection (2)) between the relay server 12 and the relay server 22 with respect to the relay server 22 (step S18: connection (2)). The relay server 12 associates connection (1) and connection (2). In establishing connection (2), the flow of processing in which IPv6 communication and encryption communication are employed is the same as ack for steps S16.1 and S16.1.

  The relay server 22 establishes a connection (connection (3)) between the relay server 22 and the client terminal 21 using the client terminal information 74 with respect to the client terminal 21 (step S19: connection (3)). The relay server 22 associates connection (2) and connection (3). In establishing connection (3), the flow of processing in which IPv4 communication and non-encrypted communication are employed is the same as ack for steps S16.1.1 and S16.1.1.

  With the above processing flow, as will be described below, the client terminal 11 and the client terminal 21 can continuously transmit and receive data in both directions. In data transmission / reception, the flow of processing for selecting a communication method is the same as that in step S16, step S16.1, step S16.1.1, and ack for these steps.

  A case where the client terminal 11 continuously transmits data to the client terminal 21 will be described. The client terminal 11 transmits data in connection (1) (connection (1): send ()). When the relay server 12 receives data in the connection (1), the relay server 12 refers to the association between the connection (1) and the connection (2), thereby transmitting the data in the connection (2) (connection (1): recv ( ) == connection (2): send ()). When the relay server 22 receives data in the connection (2), the relay server 22 refers to the association between the connection (2) and the connection (3), thereby transmitting the data in the connection (3) (connection (2): recv ( ) == connection (3): send ()). The client terminal 21 receives data in connection (3) (connection (3): recv ()).

  A case where the client terminal 21 continuously transmits data to the client terminal 11 will be described. The client terminal 21 transmits data in connection (3) (connection (3): send ()). When the relay server 22 receives data in the connection (3), the relay server 22 refers to the association between the connection (2) and the connection (3), thereby transmitting the data in the connection (2) (connection (2): send ( ) == connection (3): recv ()). When the relay server 12 receives the data in the connection (2), the relay server 12 transmits the data in the connection (1) by referring to the association between the connection (1) and the connection (2) (connection (1): send ( ) == connection (2): recv ()). The client terminal 11 receives data in connection (1) (connection (1): recv ()).

[Processing flow from step S20 to step S23]
FIG. 17 shows a flow of processing for disconnecting a connection after continuously transmitting and receiving data. In FIG. 16, the client terminal 11 transmits connection establishment request information to the client terminal 21. In FIG. 17, the client terminal 21 transmits connection disconnection request information to the client terminal 11.

  The client terminal 21 transmits connection disconnection request information to the relay server 22 in stream (3) (step S20: close ()). The flow of processing in which IPv4 communication and non-encrypted communication are adopted in the connection disconnection request is the same as ack for step S16 and step S16.

  The relay server 22 refers to the association between stream (2) and stream (3) (stream (2): close () == stream (3): close ()). The relay server 22 transmits connection disconnection request information to the relay server 12 in stream (2) (step S20.1: close ()). The flow of processing in which IPv6 communication and encryption communication are adopted in the connection disconnection request is the same as ack for Step S16.1 and Step S16.1.

  The relay server 12 refers to the association between stream (1) and stream (2) (stream (1): close () == stream (2): close ()). In the stream (1), the relay server 12 transmits connection disconnection request information to the client terminal 11 (step S20.1.1: close ()). The flow of processing in which IPv4 communication and non-encrypted communication are adopted in the connection disconnection request is the same as ack for Step S16.1.1 and Step S16.1.1.

  The client terminal 21 disconnects connection (3) from the relay server 22 (step S21: disconnect (3)). In disconnecting connection (3), the flow of processing in which IPv4 communication and non-encrypted communication are employed is the same as ack for step S16 and step S16.

  The relay server 22 refers to the association between the connection (2) and the connection (3) (connection (2): disconnect == connection (3): disconnect). The relay server 22 disconnects connection (2) from the relay server 12 (step S22: disconnect (2)). In disconnection of connection (2), the flow of processing in which IPv6 communication and encryption communication are employed is the same as ack for steps S16.1 and S16.1.

  The relay server 12 refers to the association between connection (1) and connection (2) (connection (1): disconnect == connection (2): disconnect). The relay server 12 disconnects connection (1) from the client terminal 11 (step S23: disconnect (1)). In disconnecting connection (1), the flow of processing in which IPv4 communication and non-encrypted communication are employed is the same as ack for steps S16.1.1 and S16.1.1.

{Summary of data transmission and reception}
In a relay communication system, a remote LAN may communicate over a WAN. Here, different communication methods may be employed as communication methods within the LAN and WAN.

  When transmitting data over the WAN to the receiving side, the transmitting side does not specify the IP address of the receiving side as a data destination. Then, the relay server does not determine the data transfer destination by referring to the receiving side IP address as the data destination. That is, an IP address that is not set in the same system in the entire relay communication system is not used in data transmission / reception over the WAN.

  When transmitting data across the WAN to the receiving side, the transmitting side specifies identification information on the receiving side as a data destination. Then, the relay server determines the data transfer destination by referring to the reception side identification information as the data destination. That is, the identification information that is uniformly managed in the entire relay communication system is used in data transmission / reception over the WAN.

  The relay server has relay group information, relay server information, client terminal information, network setting information, and encrypted communication setting information. Then, the relay server determines the data transfer destination by comparing the receiving side identification information with the relay group information, the relay server information, and the client terminal information. Further, the relay server determines the data transfer communication method by comparing the data transfer destination with the network setting information and the encryption communication setting information.

  Since the relay server determines the data transfer destination based on the identification information on the receiving side, it differs from a normal router. Since the relay server determines the data transfer communication method based on the data transfer destination, it differs from the normal encryption / decryption gateway. As long as the receiving side identification information is designated as the data destination, in the data transmission / reception in one section, it is only necessary to consider the communication scheme in one section without considering the communication scheme in another section. The relay communication system can easily achieve flexible operation in which the communication method in each section is an independent method.

  In the present embodiment, IPv4 communication and non-encrypted communication are adopted as the communication method in the LAN, and IPv6 communication and encrypted communication are adopted as the communication method in the WAN. However, the communication system in the LAN and WAN is not limited to the above communication system.

  In the present embodiment, any one of IPv4 communication and IPv6 communication is adopted, and any one of encrypted communication and non-encrypted communication is adopted. However, the communication option is not limited to the above communication options.

It is a figure which shows the whole structure of a relay communication system. It is a figure which shows the component of a relay server. It is a figure which shows the specific example of relay group information. It is a figure which shows the specific example of relay server information. It is a figure which shows the specific example of client terminal information. It is a figure which shows network setting information. It is a figure which shows network setting information. It is a figure which shows encryption communication setting information. It is a figure which shows encryption communication setting information. It is a figure which shows the flow of information sharing. It is a figure which shows the information stored after step S2. It is a figure which shows the information stored after step S4. It is a figure which shows the information stored after step S7. It is a figure which shows the information stored after step S11. It is a figure which shows the flow of data transmission / reception. It is a figure which shows the flow of data transmission / reception. It is a figure which shows the flow of data transmission / reception.

Explanation of symbols

1, 2 LAN
3 WAN
11, 21 Client terminal 12, 22 Relay server 31 SIP server 121, 221 Interface unit 122, 222 Control unit 123, 223 Database storage unit 124, 224 Relay group information storage unit 125, 225 Relay server information storage unit 126, 226 Client terminal Information storage unit 127, 227 Network setting information storage unit 128, 228 Encryption communication setting information storage unit

Claims (6)

A relay server capable of communicating with a first relay server connected to a first network and functioning as a second relay server connected to a second network;
A relay group information creating unit that creates relay group information indicating that the first relay server and the second relay server constitute a relay group;
The first relay server includes first relay server activation information indicating an activation state of the first relay server, and a connection state between the first relay server and a first client terminal connected to the first network. First relay terminal information created by the first relay server, including first client terminal registration information related to the registered first client terminal,
The second relay server includes the second relay server activation information indicating the activation state of the second relay server and the connection state between the second relay server and the second client terminal connected to the second network. Second relay terminal information created by the second relay server, and second client terminal registration information related to the registered second client terminal,
Relay server information including the relay group information, and the relay group sharing unit that shares the relay group information between the first relay server and the second relay server,
An inter-client-terminal sharing unit that shares the relay group information and the relay server information between the second relay server and the second client terminal;
A communication execution unit that executes communication relayed by the second relay server for a destination selected based on the relay group information and the relay server information;
With
The communication execution unit can set different communication methods for communication destined for a terminal in the second network and communication destined for a terminal in the first network,
The communication execution unit
A transfer destination determination unit that determines a transfer destination by comparing the identification information specified as the destination with the identification information described in the relay group information and the relay server information;
A communication method determination unit that determines a communication method for the transfer destination based on the transfer destination;
Including a relay server. The relay server according to claim 1,
The communication method determining unit
An address setting information creating unit that creates address setting information that associates the transfer destination with an address setting method for the transfer destination;
An address setting method determination unit for determining an address setting method for the transfer destination based on the transfer destination and the address setting information;
Including a relay server. In the relay server according to claim 1 or 2,
The communication method determining unit
An encryption communication setting information creating unit for creating encryption communication setting information for associating the transfer destination with the encryption communication method for the transfer destination;
An encryption communication setting method determining unit for determining an encryption communication setting method for the transfer destination based on the transfer destination and the encryption communication setting information;
Including a relay server. A first network, a second network,
A first relay server connected to the first network;
A second relay server connected to the second network;
A relay communication system comprising:
The first relay server and the second relay server are:
A relay group information creating unit that creates relay group information indicating that the first relay server and the second relay server constitute a relay group;
Including
The first relay server is
The first relay server includes first relay server activation information indicating an activation state of the first relay server, and a connection state between the first relay server and a first client terminal connected to the first network. A first relay server information creating unit that creates first relay server information including first client terminal registration information relating to the registered first client terminal;
Including
The second relay server is
The second relay server includes the second relay server activation information indicating the activation state of the second relay server and the connection state between the second relay server and the second client terminal connected to the second network. A second relay server information creating unit that creates second relay server information including second client terminal registration information related to the registered second client terminal;
Including
The first relay server and the second relay server are:
Inter-relay server sharing in which the relay server information including the first relay server information and the second relay server information and the relay group information are shared between the first relay server and the second relay server. Part,
Including
The first relay server is
A first inter-client-terminal sharing unit that shares the relay group information and the relay server information between the first relay server and the first client terminal;
Including
The second relay server is
A second inter-client-terminal sharing unit that shares the relay group information and the relay server information between the second relay server and the second client terminal;
Including
The first relay server is
A communication execution unit for performing communication relayed by the first relay server for a destination selected based on the relay group information and the relay server information;
Including
The communication execution unit can set different communication methods for communication destined for a terminal in the second network and communication destined for a terminal in the first network,
The communication execution unit
A transfer destination determination unit that determines a transfer destination by comparing the identification information designated as the destination with the identification information described in the relay group information and the relay server information;
A communication method determination unit that determines a communication method for the transfer destination based on the transfer destination;
A relay communication system comprising: The relay communication system according to claim 4,
The communication method determining unit
An address setting information creating unit that creates address setting information that associates the transfer destination with an address setting method for the transfer destination;
An address setting method determination unit for determining an address setting method for the transfer destination based on the transfer destination and the address setting information;
A relay communication system comprising: In the relay communication system according to claim 4 or 5,
The communication method determining unit
An encryption communication setting information creating unit for creating encryption communication setting information for associating the transfer destination with the encryption communication method for the transfer destination;
An encryption communication setting method determining unit for determining an encryption communication setting method for the transfer destination based on the transfer destination and the encryption communication setting information;
A relay communication system comprising:

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