Design And Implementation Of Sip-Based Voip System On Set-Top Box

The rapid development of the Internet not only shortened the distance between people around the world, so that communication becomes an interactive activity of anywhere and anytime, but also promoted the Internet revolution. There are internet-based products everywhere, and countless innovative products are conceived and born. This has brought unprecedented challenges for the traditional basis industry especially for the telecommunications industry.Traditional means of communication is extremely simple, voice or text is the primary means of communication. Because of the closed traditional telephony network, making routing calls cost very much and only by landline or mobile phone. In today’s highly developed Internet, it increasingly shows the limitations of the telephone network. Today, many of the individuals or groups from all over the world are trying to promote the popularization of VoIP telephone. This is a communication system relies on the internet, and it adapt to people’s traditional communication habits. Not also it greatly reduces the cost of call making, but extended single voice call to multimedia communications such as video call and you can interconnect any devices which accessed the internet.This study is based on VoIP technology. It combined with the use of the SIP protocol and embedded multimedia device as well as put VoIP technology into everyday multimedia network devices. It researched and designed the telephony network functionality in embedded devices. And it related auxiliary module to achieve a VoIP systems which devote to every consumers and runs on set-top box. On this basis, it studies of the VoIP security-related technologies further, and finally designed the practical solutions. The main contents are: In-depth study of embedded systems development technology and SIP protocol specification, in-depth reading and research the oSIP protocol stack source. And then on the basis of this designed the practical transplanting program of SIP protocol.Divided the VoIP system into multiple sub-modules. Including the IP telephone module, voice box drive module, the configuration module, the call logic module, and QT graphical user interfaces. And designed the details of each module.Packaged the C++interface on top of a layer of oSIP protocol stack, Andtransplanted to the VoIP system. Combined with RTP protocol stack and open source codecs and other related modules. Ultimately achieved IP module.In-depth studied of data security-related technologies and data encryption algorithm RSA and DES. Use DES algorithm to encrypt on real-time voice data. At the same time use the RSA algorithm to encrypt the DES keys. Finally using the SDP protocol to manage the encrypted keys and Implemented the entire encryption proces.The issue eventually completed the development of SIP-based VoIP system set-top box. And on this basis, designed and implemented the data security transportation. Eventually the system passed the test in a laboratory environment.