Patent ID: 7817668

Claim:
A communication terminal device capable of transmitting data to a receiving terminal device by simultaneously using respective ones of a plurality of paths, comprising: a path information manager unit configured to manage TCP control information related to each of the respective ones of the plurality of paths; a transmission segment manager unit configured to store segments generated by dividing data to be simultaneously transmitted to the receiving terminal device along the respective ones of the plurality of paths; and a segment transmitter unit configured to extract a segment from the stored segments and to transmit the extracted segment to the receiving terminal device along the path associated with the extracted segment, wherein the transmission segment manager unit is configured to make a reservation for transmission of the extracted segment based on the TCP control information by storing the extracted segment in association with a path used for the transmission of the extracted segment, wherein the transmission segment manager unit is configured to cancel reservations for transmission of segments which have not received a receipt acknowledgement signal and which have a sequence number not larger than the largest sequence number among sequence numbers representing segments having received a selective receipt acknowledgement signal and segments which have not been transmitted, when there are a predetermined number of segments or more having not received a receipt acknowledgement signal between a segment which has received the selective receipt acknowledgement signal and which has the largest sequence number, and a segment which should receive a receipt acknowledgement signal next, and to make reservations again for the transmission of the segments based on the TCP control information.