The Design And Implementation Of A SIP-based VoIP System

Along the development of Internet technology, the telecommunications industry is also developing new technologies to follow the trend of development of the Internet. Voice over Internet Protocol(VoIP) technology as the traditional public switched telephone network(PSTN) is an important complementary technology. VoIP technology integration of Internet technology and telecommunications technology.It uses packet switching technology to achieve the interoperability of voice, on this basis,it has developed a number of other value-added services. Compared to traditional telecom networks, VoIP technology in terms of scalability and cost have a huge advantage. Although the Qos of VoIP technology still has space to progress, but with the deepening of the study, these issues will be able to be properly addressed.According to the technical background of VoIP and related technologies such as Opus, PortAudio, RTP, SIP protocol. proposed a SIP-based VoIP system's architecture,which uses C / S structure, including client and server. On the client side used Port Audio,Opus and RTP to achieve audio model, design and implement a SIP call state machine. On the Server side design and achieved the user agent module, registration module and redirection module. Finally, the system has completed test.The test result shows that each client can achieve interoperability of text and voice,the system completes the description of the SIP voice systems. The VoIP system will have a good bussiness prospects through the further development.