The Video Conference System Based On Sip Protocol Implementation

Widespread application of Internet and the increasing development of digitalcommunications have greatly changed the traditional way of people’s life, whileincreasing people’s needs have greatly promoted the progress of the related networktechnology. In all applications of network technology, Internet-based multimediacommunication plays a very important role in people’s lives. With the development ofthe Internet, IP technology has become a ubiquitous technology in various fields, thusdriving the emergence of a variety of IP-based applications, video conferencing systemsis one of the important applications.As an important application, video conference system is firstly proposed in1960’s.In the last decades,it develops from analog technology to digital signaltechnology, and from the private network to the public network. However, it can notprovide high quality video on conference communications for the public because of thenetwork technology and cost problems. IMS proposed a new impetus for thedevelopment of video conferencing systems.The H.323protocol offered by ITU-T andthe SIP protocol proposed by IETF are current signaling protocols in a multimediacommunication system. As an application-layer control protocol, SIP is simpler, moreopen, more compatible and more scalable than H.323, which has helped it to be the coreprotocol of3G IMS.Firstly, this paper analyzes the research status of the SIP application and illustratesthe significance of this thesis. Secondly, the basic concepts of SIP has been described,including its concepts, the development process, the logic function entity hierarchy,protocol architecture, SIP messages, SIP services, SIP call flow (for examples of themore common types of call flow), and the advantages of SIP, it also compared SIP withH.323. Thirdly, based on the analysis of the SIP protocol, this paper proposes a kind ofSIP-protocol-based communication system. And it makes an introduction of the designand implementation of OSIP protocol stack, the encoder of video, the video capturetechnology (VFW), the RTP transport module, whiteboard module and the instantmessage module. Each module is given a detailed workflow, and it also gives the programming realization of some modules. Fourthly, we have a little analysis andselection of the SIP server, and miniSipServer is used as a test server for the multimediacommunication system. Fifthly,we have an experiment to test the function of the system,and the result shows that the design goals of the system have realized. Finally, asummary of the above work is made.