Patent ID: 8005893

Claim:
A relay server connected to a first LAN and arranged to communicate via a WAN with another relay server connected to a second LAN, the relay server comprising: an account information registering unit arranged to store account information about a client terminal connected to the first LAN; a relay group information registering unit arranged to store relay group information including information about the relay server and the another relay server and account information about a client terminal connected to each of the relay server and the another relay server via the first and second LANs, respectively; a shared resource information registering unit arranged to store shared resource information including: the name of a file or a folder defining a resource; information about an owner client terminal which is a client terminal capable of operating the resource; information about resource sharing client terminals that share the resource; and message information to be transmitted from one of the resource sharing client terminals, the message information being related to the resource; an operation instruction relay processing unit arranged to, when accepting an operation instruction of a resource from one of the resource sharing client terminals, specify the owner client terminal based on the shared resource information, specify a relay server connected to the specified owner client terminal based on the relay group information, and relay the operation instruction to the specified relay server; and a shared resource information relay processing unit arranged to, when accepting the message information to be transmitted from the one of the resource sharing client terminals, store the message information and information about the one of the resource sharing client terminals which has transmitted the message information in the shared resource information, specify at least another relay server connected to at least another one of the resource sharing client terminals based on the relay group information, and relay the message information to the specified relay server.