PURPOSE: To facilitate connection to shared resources on a network to be utilized by a client and data exchange between clients or between the client and a server.

CONSTITUTION: This adapter is provided with a network interface 35 for the connection to the network, plural client interfaces 31-34 for the connection to the clients, input/output relation storage part 38 for storing the combination of inputs/outputs between the network interface 35 and the plural client interfaces 31-34, and input/output control part 36 for exchanging data between the network interface 35.and the plural client interfaces 31-34. Corresponding to a command received through the respective interfaces, the relation of inputs/ outputs between those interfaces is set and stored in the input/output relation storage part 38 and according to the input/output relation stored in the input/ output relation storage part 38, data are exchanged between the respective interfaces.