opensips是一个成熟的开源SIP服务器，除了基本的SIP代理和SIP路由外，还能实验一些功能级的应用-OpenSIPS is a GPL licensed SIP server implementation. It started as a fork of Fokus Fraunhofer SIP Express Router (SER) project. OpenSIPS wants to be a more open project, not only from license