一种基于astgo回拨系统的网络电话，对接astgo 7.0软交换系统，带广告功能-A network call based on the astgo callback system

linphone软电话源码，可以作为参考，应该是写软电话很好的参考物(Linphone soft phone source code, can be used as a reference, should be a good reference to write soft phone.)