Analyse And Design Of SIP Based IP-PBX System

With developing of the modern communications technology flourish same, the enterprise's survival and sustainable development depends on low cost and high efficiency. With the development of companies, more and more branches set up, all these will bring high communications costs, a large number of domestic long-distance calls,international long-distance and the use of fax, bring huge business spending and a heavy load to the company. This huge expenditure would have been accompanied with the development of companies and will trouble them for a long time. The importance and urgency make enterprises have a clearer understanding of how to choose the communication and communication technologies. In order to work more efficiently, it is necessary for companies to integrate the various communications network of branches as soon as possible. With the continuously increment of information flow on Internet, various business on Internet are developing so fast. IP-PBX is one of them.This paper analyzes the background and development of the IP-PBX, and fingers out the purpose of the study and practical significance. And then this paper studies the SIP and function systematically. On the basis of the detailed analysis of SIP media structure and negotiate the SDP agreement, this paper focuses on setting up the basic call process. Besides, SDL (Specification and Description Language) standards, which the IP-PBX system used on the design phrase, is introduced briefing. Also, the paper analyzes network architecture, the layer analysis and modular design of the IP-PBX's control system, focusing on the detailed design of database and registration and proxy module. Finally, the paper puts some simulations to prove the feasibility of this system.The SIP based IP-PBX system proposed in this paper has met the user's requirement.