Patent ID: 7536466

Claim:
A sending-receiving system comprising a sender apparatus for transmitting data and a receiver apparatus for receiving said data transmitted by said sender apparatus; wherein said sender apparatus includes: an acquiring section for acquiring said data; a supplementing section for supplementing acquired data acquired by said acquiring section with sequence information for indicating a sequence of said data; a sending section for transmitting to said receiver apparatus said data supplemented with said sequence information by said supplementing section; a determining section for determining whether or not predetermined data is included in said acquired data, the predetermined data having a particular field set as a predetermined value in the sequence information; a storing section for storing said data supplemented with said sequence information by said supplementing section, wherein, when said determining section determines that the predetermined data is included in said acquired data, said storing section stores the predetermined data and a header attached to said predetermined data, and wherein, when said determining section determines that the predetermined data is not included in said acquired data, the supplemented data is discarded and said storing section does not store the supplemented data; and an ordering section for ordering said sending section to transmit the data retrieved from said storing section upon elapse of a predetermined time period following transmission of said data by said sending section; and wherein said receiver apparatus includes: a receiving section for receiving said data transmitted by said sending section; a determining section for determining whether or not said data received by said receiving section has been received already based on said sequence information extracted from said data; and a storage controlling section for discarding said data if said data received by said receiving section is found already received, said storage controlling section further storing said data if said data received by said receiving section is not found received already.