The Research And Implementation Of Instant Communication System Based On SIP Protocol

With the rapid development of Internet technology and digital communication technology, the Internet has become more integrated into people's daily lives.People use the Internet to deliver all kinds of information and communicate with each other.Therefore, the development of the Internet also led the development of other applications based on IP technology.In this context, an important application based on Internet technology, instant communication software produced.At first,people use instant communication to transfer real-time text messages.With the development of technology, instant communication is no longer to simply pass the text information for the purpose, more additional functionality has been integrated into the instant communication software, such as application sharing, multimedia communications, file transfer, and so on. Session Initiation Protocol (SIP) is an application-layer control protocol, which is proposed by the IETF for multimedia communications on the Internet. It has simple and flexible structure. It is suitable for Internet access and easy to extend. These characteristics make it very suitable for real-time communications.Above all, the paper analyzes the research status and development trend of instant communication and SIP. Then, it in-depth studies of the SIP protocol, including its basic concept, the characteristics, structure, message format, as well as signaling processes. In addition, thers is a brief introduction to the SIP-related protocol such as RTP, RTCP, and SDP in this paper. Based on this, it proposes a SIP-based instant communication system (SIPICS) design which is depending on Windows platform.The design includs the overall system architecture and the division of each module. The system uses a typical C/S development model, using Microsoft RTC API to develop client-side software. Finally, we used miniSipServert to test a series of functionalities of the system.The test results show that the system achieves the intended purpose of the paper.