Patent ID: 7590888

Claim:
A receiving device, comprising: receiving means for receiving a segment from a transmitting device transmitting a predetermined number of successive segments; storage means for storing sequence numbers included in segments received by said receiving means; determining means, in a case that said receiving means fails to receive a block of successive segments from among a plurality of successive segments transmitted by said transmitting device, for determining whether said receiving means receives a lost segment in said block of successive segments from said transmitting device; computing means for, if said determining means determines that said receiving means has received the lost segment from said transmitting device, computing a lost segment number, the lost segment number equaling a total number of consecutive lost segments between a segment subsequent to the lost segment received from the transmitting device and an end segment of said block of successive segments which were not received; and requiring means for requiring a retransmission of a segment by notifying said transmitting device of the lost segment number computed by said computing means.