The Application Research On SIP Based Video Communication

Due to the fast growing of HTTP (Hyper Text Transfer Protocol) , IP Network now covers most part of the world. Based on that large scope coverage and features like low lost, easy to deploy and easy to implement new services, VoIP (Voice over IP) has made great progress in recent years.VoIP technique means using IP network to transfer medias including audio, video and other types. It has three popular related protocols: H.323, MGCP (Media Gateway Control Protocol) and SIP (Session Initiation Protocol), among them SIP is accepted by most. SIP only defines basic signaling message transfer capability, making it very easy to build services based on it, and because it's submitted by IETF (Internet Engineering Task Force) and based on available IETF protocols such as SDP, RTP and so on, its structure is very clear. This thesis will study deeply through protocol analysis and implementation of video service using SIP.In this thesis, firstly, several signaling protocols, such as SS7, H.323, SIP and MGCP are introduced and compared, and the advantages and disadvantages of different networks and signaling systems are analyzed. Secondly, several parts involved in a communication process, including transporting real-time data with IP, NAT and firewall traversal, signaling interoperation and some other typical communication procedures based on SIP.Based on the above analysis, open source protocol stack oSIP and DSP BSP15, this thesis implemented an embedded SIP video phone and built a SIP communication system combined open source SIP proxy server sipXpbx. This thesis has developed corresponding implementation and tested different...