Sip Protocol Analysis And Applied Research

With the development of data business, traditional telecommunications networks which mainly undertake voice operation are faced with large-scale reform and change in order to adapt to the next-generation network (NGN) development which focuses on operation. It is well known that the softswitch is the central of the Next Generation Network (NGN) and the Session Initiation Protocol (SIP) acts as a kernel role of network protocol. Therefore, it is a hot issue in the research of the SIP and its application in the softswitch.Firstly, this thesis analyzes the softswitch technique which is the central technique of NGN and the SIP which is the central protocol of softswitch technique. Secondly, considering the issues of current softswitch and the characteristics of the SIP, this thesis, based on studying the principle and structure of SIP protocol, mainly studies the design plan of SIP_STACK and then proposes a way to implement it.Finally, the thesis analyzes and studies the typical application of SIP in current softswitch systems: (1) a model of video conference based on SIP, (2) the application of SIP in the IMS system, (3) the application of SIP in SoftX3000, and proposes a corresponding solving project.According to the test results, it is clear that the design plan and partly implement project proposed by this thesis have solved the main application problems of SIP protocol under softswitch system, such as the design of protocol stack and intercommunication issues. The following job is to perfect the design and implement of SIP protocol stack and strengthen the application of the protocol stack in practical system resulting in a sound foundation for large-scale commercial application.