A TOE (TCP/IP Offload Engine) can transmit data to and receive data from a network without causing a plurality of high order processes to influence each other in a computer mounted by a plurality of processors, each of which is mounted by a plurality of cores. The TOE 101 generates a notification queue for each high order process. The TOE driver 102 holds information that tells which high order process corresponds to which socket and which notification queue. When transmitting data, the outgoing data are temporarily held on the transmission buffer queue 102-4 and the transmission buffer is added to the notification queue that corresponds to the relevant high order process after the transmission. When receiving data, the incoming data are stored in the reception buffer on the reception buffer queue 102-3 and the reception buffer is added to the notification queue that corresponds to the relevant high order process.