(TCP) The most common transport layerprotocol used on Ethernet and the Internet.It was developed by DARPA.TCP is the connection-oriented protocol built on top of Internet Protocol (IP) and is nearly always seen in the combination TCP/IP (TCP over IP).It adds {reliable communication} and {flow-control} and provides {full-duplex}, process-to-process connections.TCP is defined in STD 7 and RFC 793.User Datagram Protocol is the other, connectionless, protocol that runs on top of IP.(2001-06-14)