为了让我们好的了解HTTP协议的工作机理，以便开发出方便用户使用的网络资源浏览应用程序。从HTTP出现到制定相应的RFC，HTTP的版本经历了HTTP0.9 、HTTP1.0、HTTP1.1。随着协议的不断完善和面向对象开发工具的不断发展，基于协议的应用程序的开发也相应的变得容易起来。

PJSIP has been actively developed since 2003, but its history goes well beyond that. The author has been developing SIP stack since 1999 during RFC 2543 era, and after several experimentation with different approaches in the programming (the first st

libike is a cross-platform C library for managing IKE negotiations. The library implements RFC-standard ISAKMP/IKE exchanges and utilizes a callback mechanism to delegate tasks of the actual packet transmission and security policies management to the