Design Of A Embedded Voice Terminal Platform Based On SIP Protocol

VoIP (i.e. Voice over IP) is the mostly direct achievement of the fusion of Telecommunication Network and Computer Network. The most development method of VoIP terminal is based on SOC solution which integrated protocol and codeing interface or low-level DSP chip currently.In view of the present voice terminal have more problem, for example single function, upgrade difficulties, fewer interfaces, low scalability and so on. The target of design that presented in this paper is to realize a VoIP terminal platform using SIP protocol. The terminal can be used as IP phones to perform voice-call function; at same time, the resource and interface are abundantly prepared for upgrade both on computing capability and software system. Successful cutting the kernel of Embedded WinCE operating system and transplanting the system to the terminal platform. We completed the compiling of the SIP protocol and voice codec library. According to the target of the design, we wrote the audio driver and application software.In this paper, first briefly described the background of the topics, purpose of the study subjects. The key technologies involved in VoIP was firstly analysed and summarized, including voice process, signal protocol. And the network structure, protocol format, call process of SIP was detailedly researched. Upon analysis and selectness the hardware platform, the entire Software Development Platform was be investigated.It include transplanting of the operating system, development of the audio driver and the application software. The test is performed according to design target, including voice-call test, protocol operation test. The testing result is submitted. In the end, the paper concludes a list of problems of the research and makes a prospect of the following development.