PJSIP中的PJSUA和Simple_pjsua例程，PJSUA使用PJSIP协议栈实现了软电话的几乎所有功能，包括注册、拨打、回应等等。simple_pjsua在不到200行的代码中实现了最简单的拨打和接听电话功能-PJSIP in PJSUA and Simple_pjsua routines, PJSUA use PJSIP protocol stack to achieve a soft phone almost all functions, including registration, call, respond, and so on. simple_pjsua in less than 200 lines of code to achieve the most simple to make and receive phone