The Design And Implementation Of SIP/WebRTC Conversion Gateway

As the product of the rapid development of HTML5, WebRTC(Web Real-Time Communications) succeeds to meet people’s needs on the Web based real-time audio and video communication. By embedding the multimedia processing capabilities into browsers, WebRTC enables users to communicate via audio or video at the webpage without installing plugins or client, which is the future trend of the real-time communication. SIP as the core protocol of IMS, has become mature and been widely applied. Implementing WebRTC and IMS, that is to achieve real-time communication between WebRTC applications and SIP terminals, is an important development direction of current real-time communication field. This will be conducive to the rapid development of WebRTC, and will also promote the real-time communication field under the coming of a new era.This paper, by studing deep into the SIP, WebRTC and the other related technologies, proposed the signaling and media separation structure of conversion gateway, achieved a extensible and maintainable SIP/WebRTC conversion gateway, and finally reached the purpose of audio and video communication between SIP terminals and WebRTC applications.Firstly, this paper introduced the SIP, WebRTC and related technologies, including the overall framework of WebRTC technology, as well as WebSocket, JSEP, SDP, SRTP/RTP, ICE, SIP and other protocols specification. Secondly, the paper analyzes the requirements of the SIP/WebRTC conversion gateway from two layers: the signaling and the media, and introduced the current solutions of SIP/WebRTC communication. Again, based on the requirement analysis, the paper proposed an idea of SIP and WebRTC gateway structure conversion where the signaling and the media are separated. It also detailly described the design and realization of the signaling gateway and the media gateway, which includes the communication between signaling gateway and media gateway. Finally, this paper introduced the implementation of a WebRTC application equipped with basic audio and video communication abilities, and through the real-time audio communication in the webrtc application and SIP terminal, made a testing on the SIP/WebRTC conversion gateway, then gave the test results and analysis.