FILE TRANSFER METHOD

摘要

PROBLEM TO BE SOLVED: To obtain a high-speed error-free file transfer method even in one- to-one communication carried out through a satellite line by using the Internet protocol through sending and receiving of control information by using TCP and sending and receiving data information by UDP. SOLUTION: A TCP connection is established between a transmission and a reception side (1). The transmission side informs the reception side of request- to-send control information via TCP (2). The reception side replies the request- to-send control information to the transmission side through TCP (3) with transmission start request control information. The transmission side, once receiving the transmission start request control information, sends packets starting with a sequence number 0 to the reception side immediately via UDP (4). The reception side periodically informs the transmission side of the number of actually normally received packets through UDP (5). The transmission side informs, after sending a file, the reception side of transmission end control information via TCP (7).