The present invention has enabled computing resources existing in domestic network systems to be utilized with a maximum efficiency. Actual condition of the connection of client apparatuses to a domestic network and overall computing resources of the domestic network are integrally controlled by a personal computer functioning itself as a private server. When a PDA outputs a request to a personal computer for downloading image data on a server, the image data is downloaded and stored in a hard disk area owned by the personal computer and offered to the PDA. A connected condition of the client apparatuses to the domestic network is constantly monitored. Even when any of the client apparatuses is provisionally disconnected from the network, proper service is continuously rendered by applying the computing resources offered to the client apparatus.