Based On Sip Voip Client Software Design And Implementation

With the development of Internet and the multimedia communication technology, the traditional Tele-service is closely integrated with Internet service.IP phone is becoming one of the most rapidly developing application technologies. The service in the NGN needs the new signal control protocol superior to H.323. The SIP protocols are simple, flexible and easily to expand. It is accounted to the important signal technology in the NGN.SIP is an application-layer control (signaling) protocol proposed by IETF for creating, modify and terminating session.The structure of the VOIP system and the relative technologies including audio coding/decoding and signal control technologies are discussed in this article. The SIP stack's syntax, entity and communication between the two entities are described too.The emphasis of this article is the realization of UA based on the open SIP stacks. It includes putting forward a procedural model to dealing with SIP events and compiling the program to realize the UA's functions in the Windows. Verification of UA's functions is gets in the Windows and MCF5235 developing platform.Last, farther researches direction is pointed out in the end.