Patent ID: 8533330

Claim:
A relay server which is connected to a LAN and which can communicate via a WAN with at least one different relay server connected to a different LAN, the relay server comprising: an account information registering device arranged to store information about client terminals connected to the LAN to which the relay server is connected; a relay group information registering device arranged to store relay group information including information about a group of relay servers which includes the relay server and the at least one different relay server and permits access to each other, and information on the client terminals registered in the respective relay servers; and a controller arranged and programmed to: exchange the relay group information between the group of relay servers; automatically update the relay group information when any relay group information is changed; receive a connection request from a client terminal, the connection request including logon information including an ID or a password; determine whether information about the client terminal which transmitted the connection request has been registered in the account information registering device of the relay server; if the client terminal which transmitted the connection request has not been registered in the account information registering device of the relay server, check the relay group information stored in the relay group information registering device of the relay server to identify a different relay server of the at least one different relay server in which the client terminal which transmitted the connection request is registered; inquire of the identified different relay server whether the logon information including the ID or the password received from the client terminal having transmitted the connection request is correct; receive a notice that the client terminal having transmitted the connection request is valid, from the identified different relay server; and accept the connection request from the client terminal to the relay server.