期刊文章，主要介绍SIP协议的即时通信系统的设计与实现，及扩展SIP协议的安全性分析-Journal articles, mainly introduces the SIP protocol instant messaging system design and implementation, and expansion of the Security Analysis of SIP-

MSN协议，适合想编即时通信系统或做网络实验时参考，写的非常详细-MSN protocol for instant messaging system to compile or make reference to the network experiments, write a very detailed