The Design And Implementation Of The SIP-Based Phone

SIP (Session Initiation Protocol) is an application layer protocol, whose main role is to establish, modify and terminate multimedia session. It not only will become the network telephone key protocol in the future, but also play a main role in IP multimedia system which is designed for future network system.First,the generation and development of VoIP is introduced and two kinds of widely used VoIP protocol is compared.Then,the construction of SIP message is discussed in detail,the concept of transaction and dialog in SIP are also explained comprehensively.At the same time, oSIP and eXosip (a SIP Protocol Implementation) structure and processing mechanism are presented. The core of this thesis is to introduce a SIP soft phone implementation, including SIP UA, user interface and static image capturing. Finally through the network packet capture tool, interaction between two SIP phone is tested, and the capture results is listed, analysis show that the signaling control of the SIP phone is right, UA achieves successfully.