Design And Prototype Implementation Of SIP Multi-party Video Conference System

Along with the development of computer, communication and Internet technology, video conference system as the typical delegation of new multimedia applications is more and more concerned. At the same time, SIP (Session Initiation Protocol), which was designed to control multimedia session, stands out for its independence from under level protocol, concision, flexibility and expansibility. So video conference system based on SIP becomes more and more popular in research domain. Many framework of SIP conference system was put forward.Our research is carried out under such a background. In this thesis, firstly we give a brief introduce about the development of video conference system and a contrast between H.323 and SIP as main technology for video conference implementation. Secondly, we introduce the SIP protocol and SIP conference model and describe the XCON framework which belongs to tightly-coupled conference and was put forward by IETF XCON work group. Finally, we present actual design——prototype system of SIP multi-party video conference, which is based on XCON framework and meets the main needs for a video conference.In this thesis, the structure of the prototype system is put forward and the conference control protocol and media operation protocol are designed. The prototype system is composed of two parts: main conference server and media mixture server. The main conference server is implemented based on Asterisk, the famous open source VoIP software. In this thesis, we describe the composition of the main conference server and function and implementation of all the modules included in the server in detail. Following this, we show how to implement a media mixture server with the open source software, Zaptel, FFmpeg and oRTP and introduce the modules of the media mixture server and their function.The prototype system described in this thesis realizes main function of multi-party video conference. It is scalable, secure and has loosely-coupled modules and good interaction with other sip multi-party video conference.