本书是详细的sip协议入门指导书。SIP是类似于HTTP的基于文本的协议。SIP可以减少应用特别是高级应用的开发时间。由于基于IP协议的SIP利用了IP网络，固定网运营商也会逐渐认识到SIP技术对于他们的深远意义。

-This book is a detailed guide book entry sip protocol. SIP is HTTP-like text-based protocol. SIP applications can be reduced, especially senior application development time. As the use of IP-based SIP IP network, fixed network operators will also come to realize the SIP technology for their far-reaching significance.