The Design And Implementation Of VoIP System Based On SIP

The development of Internet and multimedia technology promotes the development of communication technology for the comprehensiveness, digital, intellectual ability and individuality. And it also makes it possible to realize many different vocational works, such as audio, data and image on the single Internet platform. Therefore, under such a background, the IP telephony technology, which integrates network technology and multimedia technology, has appeared and made fast development. Now it has become a strong competitor in the field of audio communication technology. Apart from those advantages of using packet switching, improving the efficiency of the channel and lowering the communication cost, using the IP telephony technology is easier to realize the expansive services and the integration with the multimedia technology, which makes it advantageous among telecommunication fields and prosperous in the future.Since 3GPP announces SIP as the nucleus protocol in the IP multimedia subsystem (IMS)of R5, ETSI and ITU-T adopts IMS in the NGN system, which makes ISP the focus of the people. VoIP's future development will adhere to SIP protocol of IETF.As a newly explored protocol, SIP is to solve the problems that exist in the telephone network, such as the complexity of telecommunication system, more cost and the difficult to protocol expansibility. It has many advantages such as better flexibility, simpler structure, shorter time of calling, distribution control, easier to increase values.With VoIP based on SIP as the main research subject, this paper discusses the relevant protocols, standard and key technology of IP telephony, analyzes this IP telephony protocol, designs a set of telephone service system based on VoIP, including system analysis, system design and system realization, and finally tests this software to achieve the expected goal. The main work of this paper is:①Putting forward a set of VoIP system that has a reasonable structure and good...