Reasearch For The SIP And Mediastreamer2 Of The IP Videophone

Along with the development of the modern communication technology, the Internet technology as well as the computer technology, the band width demand explosively grow, while the wide band user rapidly rose. That promoted the characteristic network multimedia application development such as the video, the audio, the text, the animation and so on.And that has become the part of the society life. Meanwhile, with the corresponding of the higher request, the traditional telecommunication telephone cannot satisfy the demand of people which was aggregated gradually day by day.Ppeople are more urgent to the experience of videophone, while the market of the videophone also grows strong along with it.This article uses open source software linphone to set up the foundation frame of the system. Each module's function, which is under the architecture of the system, as well as the relations between the different modules have been elaborated detailedly.That is also the solid foundation for the realization of the extended function in the system.In order to realize the sending and receiving of the instant message based on the SIP as the extended function, this article elaboratd the SIP architecture, the SIP protocol message's form, the SDP agreement, the SIP elementary operation as well as the SIP call flow,and analized the detailed research of the message transmission realization.Finally we have completed the instant message realization. For the mediastreamer processing, this article apply the Mediastreamer2 processing method to conducte the thorough research and the extend attempt to linphone.Finally we have completed realization of adding the new media class function to the above the Mediastreamer2 foundation. Since this is a practical videophone system, there are lots of problems during the process of design and realization. With a corresponding correction, the ultimate videophone can better achieve its scheduled function in the actual requirements.