STUN（RFC3489）客户端的简单实现，Internet上有很多STUN server,改程序可以检测本地和公网之间的NAT类型。-STUN (RFC3489) client to achieve a simple, Internet there are a lot of STUN server, changed the procedure can detect both local and public network between the NAT type.

linphone-3.3.0 版本，这个就不多做介绍了，知道的人都知道！如果还是不知道，那么看看下面英文的介绍吧。-Features Linphone provides a large amount of functionalities. List of supported features: * audio with the following codecs: speex (narrow band and wideband), G711 (ulaw,alaw),