References
Amongh the best references for TCP are some classic textbooks:
Douglas Comer, Internetworking with TCP/IP (and several other books that Comer wrote)
W. Richard Stevens, TCP/IP Illustrated, Vol. 1 - one of the best books ever on this subject
Listed below are just the main RFC for the TCP specification, RFC 793, and a relatively recent RFC on TCP Congestion Control. There are many other related RFCs, and the first RFC listed below, the "roadmap", can help you figure out which ones are of interest to you. In addition, you will find further references to RFCs and other resources from some of the individual tutorials in this porta.
RFC 4611 A Roadmap for TCP Specification Documents
RFC 793 TCP Protocol Specification
RFC 5681 TCP Congestion Control
The following link has some helpful discussion about topics that are covered in this portal:
TCP Related Notes by Leonardo Balliache
