Patent ID: 7594040

Claim:
A network relay device compliant with network plug-and-play protocols for relay between a network and a device unit having N service devices that provide a service in response to a request from a client on the network where N is an integer equal to 1 or greater, the network relay device comprising at least one of: a description creating module configured to create a device description which describes service devices included in the device unit connected to the network relay device; and a response module configured to respond to a device search request sent from the client in accordance with the network plug-and-play protocols, wherein if one or more service devices among the N service devices belonging to the device unit are inoperative when the description creating module receives a request for a device description sent from the client, the description creating module creates a device description that does not include a description portion of the inoperative service devices and forwards the created device description to the client, wherein the response module responds to a device search request sent from the client if at least one service device in the device unit is in operative condition, while the response module does not respond to a device search request sent from the client if all of the service devices in the device unit are in inoperative condition, and wherein if all of the N service devices are inoperative, the description creating module creates a device description that includes only a basic device that provides no services to clients.