Transport

TCP

http://en.wikipedia.org/wiki/File:Tcp_state_diagram_fixed.svg

Nagle's algorithm and TCP cork setsockopt option

http://www.baus.net/on-tcp_cork

TCP Performance problems caused by interaction between Nagle's Algorithm and Delayed ACK

http://www.stuartcheshire.org/papers/NagleDelayedAck/

TCP offload - TSO/ LRO

http://laurachappell.blogspot.com/2010/09/analyzing-huge-packets-tsolro.html

TCP MD5 signature option (used to protect BGP session against spoofing)

https://www.ietf.org/rfc/rfc2385.txt