To provide the data communication system where efficient data communication is attained even when a communication protocol of a wired channel is replaced with that of a satellite channel.
A communication server 10 provided with a communication control section 11, a packet processing section 12, a TCP packet storage section 13, a UDP packet storage section 14. A reply packet generating section 15 is placed to each site and a satellite channel LS is interposed between sites to configure the data communication system. A UDP or TCP packet being a transmission object is stored in corresponding packet storage sections 13, 14. At least at the end of one packet, the packet group is sent simultaneously to a transmission destination site. In the case that the packet group sent simultaneously is of a TCP, the transmission result based on a reply packet from the destination site is simultaneously informed to the senders who are requesting the packet transmission.
YOSHIKAWA AKIO
MASAMOTO SATOSHI
