Abstract: A relay server mainly includes a VPN group information storage unit, an address filter information storage unit, and a communication control unit. The VPN group information storage unit is arranged and programmed to store information concerning routing apparatuses that define a VPN group and a routing session. The address filter information storage unit is arranged and programmed to store address filter information in association with identification information of the routing apparatus. The communication control unit is arranged and programmed to perform controls of: upon detection of that an address included in the address filter information overlaps, causing a translated address to be associated with the overlapping address, and transmitting the translated address to another routing apparatus; and performing routing based on the address filter information and the translated address.

Abstract: In a relay communication system, when receiving an operation instruction of a resource from a client terminal stored in an account information registration unit, a relay server relays the operation instruction to a client terminal capable of operating the resource based on relay group information if the resource is operable by another client terminal.

Abstract: A relay server performs control to establish a routing session between the relay server and another routing relay server, control to establish a sub routing session between the relay server and a sub routing apparatus, and a packet forward control to forward a received packet via the routing session or the sub routing session. The packet forward control is such a control that, when a destination of a packet is associated with the sub routing apparatus of the relay server in a content stored in a sub address filter information storage unit, the packet is forwarded to the sub routing apparatus, while otherwise the packet is forwarded to the destination.

Abstract: A virtual network is dynamically created when a relay communication system is constructed including a plurality of relay servers that communicate with each other. In the relay communication system, VLAN client terminals which define a VLAN group share VLAN group information. In addition, a VLAN session is established between the VLAN devices as activatable VLAN client terminals among the VLAN client terminals based on the VLAN group information, and the VLAN devices are allowed to share virtual address information created when the VLAN group is activated. Furthermore, if the VLAN group has already been activated when instructed to activate the VLAN group, a join-in-progress signal to the VLAN group is transmitted to a join-in-progress VLAN client terminal as a transmission source of the activation instruction, and a VLAN session is established that is related to the join-in-progress VLAN client terminal and has not been established yet.

Abstract: A virtual network is dynamically created when constructing a relay communication system including a plurality of relay servers that are arranged to communicate with each other. In the relay communication system, the VLAN client terminals defining a VLAN group are allowed to share VLAN group information. In addition, a VLAN session between VLAN devices as activatable VLAN client terminals is established based on the VLAN group information, and the VLAN devices are allowed to share virtual address information created when the VLAN group is activated. If the VLAN device defining the activated VLAN group is suspended, suspension of the VLAN device is notified, and a VLAN device about which the suspension has been notified is deleted from the virtual address information. The VLAN session related to the VLAN device about which the suspension has been notified is closed.

Abstract: A virtual network is dynamically created when a relay communication system is constructed including a plurality of relay servers that are arranged to communicate with each other. In the relay communication system, the VLAN client terminals defining the VLAN group are allowed to share VLAN group information. In addition, a VLAN session is established between the activatable VLAN devices among the VLAN client terminals based on the VLAN group information, and the VLAN devices are allowed to share virtual address information created when the VLAN group is activated. The VLAN device sets the given virtual address in a VLAN interface of the VLAN device, and communicates with other VLAN device using the virtual address and VLAN session.

Abstract: In a relay server, a routing group information sharing unit shares routing group information, which is prepared by grouping routing control points including at least two of a first relay server in a relay group, a second relay server in the relay group, a client terminal connected to the first relay server, and a client terminal connected to the second relay server. A routing session establishment unit establishes a routing session, which enables a communication packet to be routed via the routing control points, for each group indicated in the routing group information while referring to relay server information.

Abstract: In a relay communication system, a method and apparatus prevent crossover among call controls in sections and crossover among communication routes in each of the sections. Relay servers relay communication between client terminals. A relay server creates information, and allows a whole of a relay communication system to share the information, which includes: relay group information indicating that the relay servers constitute a relay group; and relay server information indicating a client terminal capable of communicating with the relay server. The relay servers and the client terminals collate identification information of call control, transmitted when the call control is executed for a destination for communication in each section, and identification information of call control, received from the destination for communication in each section when a communication route is established, with each other, and allows the call controls and the communication routes to correspond to each other.

Abstract: A relay server includes a VPN group information storage unit, an address filter information storage unit, and a communication control unit. The VPN group information storage unit stores routing session information indicating identification information of routing apparatuses that define a VPN group and the routing apparatuses that are connected to one another. The address filter information storage unit stores address filter information, which indicates a partner that the routing apparatus is able to designate as a packet destination, in association with identification information of the routing apparatus. The communication control unit is programmed to perform a control to, when a VPN is started in the VPN group, update a content stored in the address filter information storage unit based on the address filter information received from the routing apparatus, and establish a routing session based on the routing session information.

Abstract: A relay server which is connected to a LAN and which can communicate with a relay server in a different LAN, includes: an account information registering unit that stores information on client terminals connected to the LAN; a relay group information registering unit that stores relay group information; a shared resource information registering unit that stores shared resource information; a check unit that checks whether the client terminals stored in the account information registering unit can be accessed; a relay group information notifying unit that updates the relay group information and transmits a change notification of the relay group information to the relevant relay server; and a shared resource information notifying unit that updates the relevant shared resource information and transmits a change notification of the shared resource information to the relevant client terminal which is stored in the account information registering unit.

Abstract: A relay device requests a status notification of another relay device to a server device. When the relay device is notified that the other relay device is under a logged-out status, the relay device stands by. When the relay device is notified that the other relay device has logged in, the relay device transmits a connection request to the server device. The server device relays the connection request to the other relay device. A response is transmitted from the other relay device to the server device, and further relayed to the relay device. Accordingly, a TCP connection is established between the relay device and the other relay device. A communication device connected to a different network can transmit and receive data to and from the relay device via the other relay device.

Abstract: A technique of carrying out communications between communication terminals on different LANs while realizing reductions in the burden of account control and suppression in load on a server includes first and second relay servers on first and second LANs issuing a registration request to a SIP-server, respectively. A first communication terminal on the first LAN issues a registration request to the first relay server while a second communication terminal on the second LAN issues a registration request to the second relay server. The first and second relay servers exchange account information about the registered communication terminals with each other. When the first communication terminal generates communication data addressed to the second communication terminal, the first relay server selects the second relay server as a relay based on the exchanged account information to relay the communication data. Then, the second relay server relays the communication data to the second communication terminal.

Abstract: A technique allows shared use of a file between different networks via the Internet. File transfer servers on different LANs access file servers on the respective LANs to prepare a list of shared files, respectively. The file transfer servers are registered in a SIP server, and then send a SUBSCRIBE method to each other to issue a request to transfer the file list, respectively. In response to the request, the file lists are exchanged. A communication terminal on each LAN makes a request to acquire a specific file on the basis of information about the shared files stored in the file transfer server. Through a media session, one of the file transfer servers issues a request to acquire the file to the other file transfer server. As a result, the file is transferred to the communication terminal.

Abstract: In a relay communication system in which remote LANs communicate with one another beyond a WAN, respective apparatuses confirm a virtual network environment of the relay communication system in real time. Relay servers relay mutual communication between client terminals. The relay server creates information shown below, and allows the whole of the relay communication system to share the information: a relay group information indicating virtual private IP addresses of the relay servers and a connection establishment state therebetween; and a relay server information indicating a virtual private IP address and connection establishment state of a client terminal capable of communicating with the relay server.

Abstract: A relay server can collectively copy a plurality of shared resources separately held by client terminals to a terminal that belongs to the relay server by performing a simple operation. The relay server includes a shared resource information registration unit. The shared resource information registration unit stores shared resource information when a resource is shared among a plurality of client terminals. The shared resource information includes resource information, hierarchical structure information regarding a hierarchical structure of the resources, and account information of a resource sharing terminal that is a client terminal that shares the resource.

Abstract: Communication is established between communication terminals arranged in different LANS while realizing dynamic response to reduction in server load, movement of communication terminal, and the like. A relay server is arranged in a LAN and can communicate with an SIP server arranged in a WAN. For instance, a first relay server exchanges account information of the communication terminals in the respective LAN with a second relay server. If exchanged account information is changed in one relay server, the account information after the change is notified to the other relay server. One relay server determines the other relay server based on the exchanged account information and relays communication data between the communication terminals through the other relay server.

Abstract: A relay server is capable of communicating with other relay servers through an external server arranged on a Wide Area Network. The relay server stores information about a registered terminal, information about the relay servers forming a relay group by permitting connection among each other, and information about a resource and a client terminal sharing the resource. When an operation instruction regarding the resource in another terminal is received, the relay server relays the operation instruction from the registered terminal to another relay server. However, when key information is stored in association with the resource, the relay server relays the operation instruction to the other relay server only when a correct key has been entered.

Abstract: In a relay communication system in which remote LANs communicate with one another beyond a WAN, a method and apparatus prevent crossover among a plurality of call controls in each of a plurality of sections and crossover among a plurality of communication routes in each of the plurality of sections. Relay servers relay communication between client terminals. A relay server creates information described below, and allows a whole of a relay communication system to share the information: relay group information indicating that the relay servers constitute a relay group; and relay server information indicating a client terminal capable of communicating with the relay server.

Abstract: In a relay server, a routing group information sharing unit shares routing group information, which is prepared by grouping routing control points including at least two of a first relay server in a relay group, a second relay server in the relay group, a client terminal connected to the first relay server, and a client terminal connected to the second relay server. A routing session establishment unit establishes a routing session, which enables a communication packet to be routed via the routing control points, for each group indicated in the routing group information while referring to relay server information.

Abstract: A virtual network is dynamically created to construct a relay communication system. Between a first relay server and a second relay server, a VLAN device information sharing unit shares VLAN device information including interface information of client terminals capable of functioning as VLAN devices in a relay group. A VLAN group information creation unit edits the VLAN device information, thereby creating VLAN group information formed by grouping the client terminals indicated in the VLAN device information. A VLAN group information sharing unit shares the VLAN group information among the first relay server, the second relay server, the client terminal connected to the first relay server, and the client terminal connected to the second relay server.