SIP是IETF致力于将电话服务带入IP网络众多协议的一个组成部分（它与SDP、RTP、RTCP、RTSP、RSVP、TRIP等众多协议构成SIP系统协议栈）. 这是sip协议栈实现最新版, 可用于开发sip客户端/代理/服务器-SIP is the IETF working on telephone services into the IP network number of an integral part of the agreement (with the SDP, RTP, RTCP, RTSP, RSVP, TRIP, and many other agreements constitute a SIP system protocol stack). This is the sip protocol stack to achieve the latest version, can be used to develop sip client/agent/server