Patent ID: 8010598

Claim:
A relay server connected to a first LAN and communicable 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 account information about the relay server and the another relay server and account information about client terminals connected to 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: a 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; information regarding whether or not the resource can be shared by an external client terminal that is not stored in the relay group information registering unit; information about the external client terminal; and information about a protocol connected to the external client terminal; a first relay processing unit arranged to, when accepting an operation instruction of a resource from 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 of the resource to the specified relay server; a converted resource information providing unit arranged to, when accepting an access based on the protocol from the external client terminal, extract a resource that can be shared by the external client terminal from the shared resource information, convert information of the extracted resource to a format of the protocol, and provide the converted resource information to the external client terminal; and a second relay processing unit arranged to, when accepting from the external client terminal an operation instruction of a resource based on the converted resource information, specify the resource that has the accepted operation instruction from the shared resource information, specify an owner client terminal of the specified resource, specify a relay server connected to the specified owner client terminal based on the relay group information, and relay the operation instruction of the specified resource to the specified relay server.