Behind Skype
An Analysis of the Skype Peer-to-Peer Internet Telephony Protocol is an interesting tech report on the workings of Skype. (Skype is a P2P VoIP client which is gaining immense popularity for it's ease-of-use, voice quality and seamless working over NATs and firewalls.) Since the technology used in Skype is not open, the authors have discovered the workings by analysing the network traffic generated by Skype. One of the authors of the report is Henning Schulzrinne, who is incidentally one of the main guys behind the development of SIP.
http://www1.cs.columbia.edu/~library...ucs-039-04.pdf
Behind Skype
