Research On IP Video Conferencing System Based On SIP

After years of research on multiple endpoints video conference based IP network, the theory and technology has been mature. With the progress of multi-media technique, video conference can be realized with lower code rate and more excellence quality of visual effect.There are mainly two protocol families about video conference, which are H.323 and SIP. The former is proposed by ITU organization, and the latter is done by IETF. H.323, which has long time of development, is more widespread in the domestic application. Compared to H.323, SIP has the incomparable superiority of having simple design thought, having better mobility and extension and the terminal device having good intelligence. Constructing multimedia conference system using SIP not only can realize the function of H.323,but also the cost is low , it is convenient to develop many kind of multiplication service and it brings a greater economic efficiency and the good social benefit. But SIP at first is proposed for the IP telephone, it mainly is used on the session connection and management between point to point. It does not have the ability of providing multiple sessions. And thus the research and implementation of multimedia conference system based on SIP exists certain difficulty and complexity. At present the conference framework of SIP is at the stage of draft, and hasn't officially become standard. Therefore researching and implementing conference system of SIP has theory and practice significance.The implementation of video conference system includes hardware implementation and software implementation. The principle of the hardware implementation is the same as the principle of the software...