TCP / Transmission Control Protocol

IETF RFC793 (http://www.ietf.org/rfc/rfc0793.txt) defines the Transmission Control Protocol (TCP). TCP is one of the main protocols of the Internet protocol suite and provides a reliable, error-checked, stream delivery and virtual connection service to applications through the use of sequenced acknowledgment with retransmission of packets when necessary. TCP originated in the initial network implementation in which it complemented the Internet Protocol (IP).