Research And Implementation Of Real-time Communication System Based On WebRTC

Real-time communication applications based on traditional C/S architecture do not support cross-platform,so developers need to develop multiple client versions for different platforms,and the development costs are extremely high.Users need to deliberately download,install and the client,and update the client,which is very cumbersome and reduces the user experience.And applications based on C/S architecture generally use private protocols,thus communications are not available between various applications.With the development of the Internet,the increasingly powerful browser features,especially the emergence of HTML5,the gap between Web App and Native App is narrowed.However,most of the current real-time communication applications based on B/S architecture need to install plug-ins.Developers need to develop based on the plug-ins.It is hard to test if problems occur,since most plug-ins need authorization,which leads to high development costs,and sometimes developers have to consider the differences between the different browser vendors.For users it is cumbersome to download,install and upgrade plug-ins,and the security risks should not be ignored.In 2010,Google acquired Global IP Solutions and acquired a new technology and made it open source in May 2011.This technology is the very popular WebRTC.WebRTC supports high-quality browser web real-time audio dialogue and video dialogue,which combines the media streaming,private network traversing,network transmission and session state machine and other functions in the process of multimedia communication,and they are packaged in the browser,not need downloading and installing like plug-ins.This paper design a communications system using WebRTC and other technologies in order to solve the flaws of current majority of applications based on C/S architecture and B/S architecture.This paper first focuses on the research of WebRTC and the P2 P,combining WebRTC with P2 P to reduce the server pressure and message delivery delay.The NAT and NAT traversal in P2 P are studied deeply,confirming the established system uses STUN for NAT traversal.As for signaling control in P2 P connection,this paper analyzes two signaling control protocol,and finally JSEP is selected to achieve signaling control.The establishment of P2 P connection requires signaling server to achieve signaling control.This paper studies the existing interaction technologies between browser and server,and selects WebSocket to achieve the interaction.In the concept of combining reality and keeping up with the trend,this paper designs three communication modules,and their data forwarding mode are studied deeply.Aiming at the difficulty of data forwarding of live module,this paper designs a dynamic hierarchical model called DHALM based on application layer multicast to establish the forwarding network of data flow of the live module.The simulation results for DHALM proved that the DHALM has small average path length,low control overhead,high data transfer rate and better robustness.Based on the difficulty of multi-person conference,this paper designs two kinds of conference modes based on P2 P full connection structure and Router structure,and analyzes the threshold of number of individuals of the two modes by simulation experiments.Finally,the system is implemented and tested over a variety of experiments,demonstrating that the performance of each module is extraordinary and achieves the desired results.