基于WebRTC的实时通信系统的研究与实现

发布时间：2018-02-23 13:39

本文关键词： WebRTC P2P 实时通信应用层组播插件跨平台　出处：《南昌大学》2017年硕士论文　论文类型：学位论文

【摘要】：传统C/S架构的实时通信应用不支持跨平台,开发人员需要针对不同平台开发多版本的客户端,开发费用极高;对用户而言,需要刻意下载、安装和升级客户端,非常繁琐。并且C/S架构的应用一般采用私有协议,各种应用不能相互通信。随着互联网的发展,浏览器功能的日益强大,特别是HTML5的出现,缩小了Web App与Native App的差距,但是目前大多数B/S架构的实时通信应用都需要安装插件才能使用,开发人员需要根据插件进行开发,出现问题很难测试,因为大部分插件都需要授权,导致开发成本太高,有时还得考虑不同浏览器之间的差异;而用户下载、安装和升级插件非常繁琐,并且存在安全隐患。2010年,谷歌收购Global IP Solutions公司得到了一项新技术,并于2011年5月将它进行了开源,这项技术就是现在非常火爆的WebRTC技术。WebRTC支持高质量的网页实时音频对话和视频对话,它集合了多媒体通信过程中的媒体流处理、私网穿越、网络传输和会话状态机等功能,并将它们封装在浏览器当中,不像插件那样需要下载安装。本文利用WebRTC与其它技术结合设计一款通信系统,致力解决目前大多数C/S架构应用和B/S架构应用存在的缺陷。本文首先重点研究了WebRTC和P2P技术,设计将WebRTC和P2P技术结合来减小服务器压力和消息传递时延,并对P2P技术涉及的NAT和NAT穿越进行了深入研究,确立了本系统使用STUN进行NAT穿越。P2P连接的信令控制方面,分析了两种信令控制协议,最终选择JSEP来实现信令控制。P2P连接需要信令服务器进行信令控制,本文研究了几种浏览器与服务器交互技术,挑选WebSocket实现浏览器与信令服务器的交互。在结合实际、跟上潮流的理念下,本文设计了三大通信模块,并为它们的数据转发方式进行了深入研究。针对直播模块数据转发的困难,本文设计了一种基于应用层组播的动态层次模型DHALM来建立直播模块的数据流的转发网络,并对DHALM进行仿真,证明DHALM平均路径长度小、控制开销小、具有较高的数据传输率和较好的鲁棒性。基于多人会议实现的难点,本文设计了基于P2P全连接结构和基于Router结构的两种会议模式,并对两种模式的人数阈值进行了实验分析。最后进行系统实现和测试,本系统通过了各种测试,各个模块性能卓越,达到了预期的效果。
[Abstract]:Traditional C / S real-time communication applications do not support cross-platform, developers need to develop multiple versions of the client for different platforms, development costs are very high; for users, the need to deliberately download, install and upgrade the client, It's very cumbersome. And the applications of the C / S architecture generally use private protocols, and all kinds of applications can't communicate with each other. With the development of the Internet, the function of browser is becoming more and more powerful, especially the appearance of HTML5, which has narrowed the gap between Web App and Native App. But at present, most real-time communication applications based on the B / S architecture need to install plug-ins to use, and developers need to develop according to plug-ins, so it is very difficult to test because most plug-ins need authorization, which leads to high development cost. Sometimes you have to consider the differences between browsers; users download, install and upgrade plug-ins that are cumbersome and secure. In 2010, Google acquired a new technology for Global IP Solutions. And in May 2011, it was open source. This technology is now a very popular WebRTC technology. WebRTC supports high quality webpage real-time audio dialogue and video conversation. It integrates media stream processing in multimedia communication and private network traversing. Network transmission, session state machine and other functions, and encapsulate them in the browser, do not need to download and install like the plug-in. This paper uses WebRTC and other technologies to design a communication system. This paper focuses on the research of WebRTC and P2P technology, and designs the combination of WebRTC and P2P technology to reduce server pressure and messaging delay. The NAT and NAT traversal involved in P2P technology are deeply studied, and the signalling control of NAT traversing. P2P connection using STUN in this system is established, and two signaling control protocols are analyzed. Finally, JSEP is chosen to realize signaling control. P2P connection needs signaling server to control signaling. This paper studies several kinds of browser-server interaction technology, selects WebSocket to realize the interaction between browser and signaling server. Under the idea of keeping up with the trend, this paper designs three communication modules, and makes a deep research on their data forwarding methods. In this paper, a dynamic hierarchical model based on application layer multicast (DHALM) is designed to establish the data stream forwarding network of direct broadcast module. The simulation of DHALM shows that the average path length of DHALM is small, and the control overhead is small. It has high data transmission rate and good robustness. Based on the difficulties in the implementation of multi-person conference, this paper designs two kinds of conference modes based on P2P full connection structure and Router structure. Finally, the system is implemented and tested. The system has passed all kinds of tests, and the performance of each module is excellent, and the expected effect has been achieved.
【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP311.52;TP393.09

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