The Key Technologies Of The Sip Protocol And Network Phone

IP Phone is one of the fastest application technology for its unique advantage of low cost and flexibility. The Session Initiation Protocol (SIP) is an application-layer control(signaling) protocol distributed by IETF for creating, modifying and terminating sessions with one or more participants. These sessions include Internet telephone calls, multimedia conferences and multimedia distribution. The personal mobility, the phone number exclusive, the convenience of media parameter negotiation, the easily extensive, all make SIP protocol as the focus of VoIP industry and 3G. IP phone has larger competition after support SIP protocol.In this dissertation, the author study the key technology of SIP protocol and make it realization in the IP phone. Through the analyze of SIP and IP phone, the author divided the IP phone into UAC and UAS, then formulated the steps and demand of developing program, which were expressed with simply flow chart, including Registration, create Dialog, initialize Session and Invite a user, modify the parameters of Session and so on.Now IP phone are all based on the PA1688 chip created by PALM Corporation, so the author finished the program by C++/C and Assemble language according to PA1688. After that explain the basic program and procedure of one call which IP phone should be done when he want to create a call. Combined the software and hardware to finish the design of SIP key technology, Now IP phone support SIP protocol and make some action to have a big drive to our country VoIP career.This dissertation is one of the first projects which research the key technology of SIP, and make it application to IP Phone in china, it is the leading in our country, also keep up with the steps of international technology. We directly did this dissertation on the base of RFC3261, as a result, make sure the advance and extensible, stick to keep update the time;Combine of the software and hardware, completely get rid of exclusive software, make sure the real time of signal and increase greatly the voice quality, and decrease the percentage of packet lost.The context was written and based on the research of RFC3261 and theYWH100 IP Phone.There are 6 chapters.The first chapter begin with the history, development and the actuality of VoIP, explain the main research, the value and the level;The second simply introduce the definition, function, syntax, module, message and structure of SIP protocol;In the third chapter, the author divide the IP phone into UAC and UAS according to SIP protocol and expatiate the key technology and flow of them, including the register, dialog, create session, maintain session, modify dialog and terminate dialog;The Fourth chapter is the system realization of SIP key technology, including software and hardware. Introduce PA1688 chip and explain the program written by author, also analyze and explain the key technology which IP phone should own during he finish a call;The fifth chapter is the main application of IP phone after supported the key technology of SIP, it can save large amounts of cost when it call PSTN phone, especially when the other end is the same IP Phone, the charge is zero;The last one is the conclusion;...