The Reserch Of Web Based Realtime Communication

With the development of the society, the Internet has become an important part of life. Compared with wireless communications, communication over the Internet is cheaper, with less limitation, and more information interaction varieties. Realtime communication over the Internet has become the most popular application.Real-time communication on the Internt can be implemented inmode of C/S or B/S. The traditional realtime communications are most implemented based on the C/S architecture.However, with the development of Web, the B/S architecture is more convenient and widely depolyed,with more users around the world. It has become more and more easy for developers to implement realtime communications such as text, audio and video call based on Web.The Web based real-time communication system hasimplemented the instant messager and video call. Different from the client based communication, Web communication requires page refreshing to exchange information.This paper discussed the page refreshing technology.We use long polling BOSH to implementWeb instant messager.To realize Web IM, this paper researched the instant messaging protocol, especially XMPP. XMPP is an open source instant communication protocol. Every XMPP entity has only one user ID. The browser doesn’t support XMPP protocol. The Web IM system introduces BOSH proxy. In the end, we test the Web IM in login, contact list, presence, chatting and logout. The system works well.Compared with text communication, Web video call is more complicated with more information and refreshing more frequently. We introduce the best solution in the World-WebRTC.WebRTC is composed with signaling panel and media panel.Signaling panel is supposed to control the media transmission signaling protocol, such as ROAP and JSEP. It introduces the state machine mechanism. Media panelis mainly responsible for media capturing, media signal processing, etc.We discussed a lot about ROAP and JSEP.We study the WebSocket protocol, and the getusermedia API, which makes the local camera and microphone lauched from Web possible.In this paper, the RTCWeb especially ROAP and JSEP are studied. By calling getusermedia API to start camera and microphone, JSEP controlling the media states, XMPP with WebSocket establishing connection and transimiting data, we implement a Web video call system. In the end,we have the Web video call system tested. The Web video call system works well, with long stable connection, smooth video image and clearspeech.