Research And Implementation Of VoIP Soft Terminal Based On SIP

With the development of technology in the network and multimedia area,the business of multimedia communication,especially the VoIP technology,which can make a real-time communication connection through IP network,has become a leading element in the Internet applications.The key technology of the development of VoIP is signalling technology. The most widely used protocols are H.323 and SIP.H.323 is the mainstream in the VoIP equipments and has been accepted in the Chinese communication market.But the Session Initiation Protocol(SIP) is very concise in the structure,easy to be extended and realized,especially more suitable to access the Internet.All these advantages show that SIP is fit for VoIP and the future development of network.So,studying the design and realization of VoIP network terminal based on SIP will be meaningful in practice usage.The network architecture and signalling flow of SIP are firstly explained in this paper, based on the analysis of VoIP service's usage and future, VoIP key technologies and main signalling protocols. The explanation of the function and grammar of the Session Description Protocol(SDP) and the real-time Transport Protocol(RTP) is followed.Then, Based on aforementioned research work and the current research situation, the requirement of the soft terminal based on SIP is analysed, which includes functionality requirement such as voice communication, instant messaging and non-functionality requirement such as performance, robust and usability.The design principle and ideas are based on the requirement and according to the requirement, the concrete introduction of the soft terminal's SIP stack is made.After that,the solution of the soft terminal is proposed referenced to the Module-View-Controller(MVC) Design...