Inventors: Taketsugu, Masanori;
Assignee: NEC Corporation (Tokyo, JP)
Primary Examiner: Le; Dieu-Minh
Assistant Examiner:
Attorney, Agent or Firm: Sughrue, Mion, Zinn, Macpack & Seas, PLLC
To enable data transmission without transmitting packer's serial numbers, a transmit serial number is incremented by one at a transmit site each time a serial numberless data packet is sent to a receive site, and a copy of the transmitted packet is stored in a transmit memory corresponding to the transmit serial number. The process is repeated so that a predetermined number of outstanding packets are transmitted. At the receive site, a receive serial number is incremented by one upon receipt of each packet and the packet is stored in a receive memory corresponding to the receive serial number. The receive site determines whether there is an error in the outstanding packets in the receive memory. If an error is found, the receive site sends a request packet containing the serial number of the packet in error to the transmit site. In response, the transmit site sends a replacement copy for the corrupted packet to the receive site which, in response, replaces the packet in error with the received copy. If no packet in error is found in the receive memory, the receive site transmits an acknowledgment to the transmit site. On receiving it, the transmit site repeats the transmission of the next sequence of outstanding serial numberless packets. |