| 摘要 |
PROBLEM TO BE SOLVED: To prevent wasteful retransmission.SOLUTION: A transfer unit 100 adds values of phase IDs every prescribed time and, while so doing, keeps the packet ID and phase ID of a transmitted data packet registered in a determination table by correlating the IDs to each other. When a response packet is received from a transfer device 200 on the receiving side, the transfer device 100 determines an unreached packet on the basis of a received packet ID included in the received packet and the packet ID of the transmitted data packet. Then, the transfer device 100 determines, from relationship between the phase ID of the unreached packet and the maximum phase of the received packet, whether a data packet relevant to the unreached packet is lost or on-the-fly. Only when determined to have been lost, the transfer device 100 retransmits the relevant data packet. |
