基于eXosip封装，充分考虑了各种SIP较色，UAC,UAC,PROXY,DIRECT,REGISTER,也就是本套库可以作为任何服务器和客户端使用。不需要关心中间的实现细节-Based on eXosip package, full consideration of the various SIP more color, UAC, UAC, PROXY, DIRECT, REGISTER, that is, the set of libraries can be used as any se