| SIP standard delivered by IETF Internet engineering task force has already become the research hotspot in the fields of telecommunication and network. With the characteristics of readability, flexibility, expansibility and robustness as well as the openness, as one of the most important protocols, SIP has been gradually replacing the important role of other protocols such as HTTP and SMTP. The video conference system based on SIP also represents its irresistible charm. As for terminals, software terminal and intelligent terminal on the basis of SIP as well has emerged in our personal computers and firm offices. As regards the provision of service, through SIP the soft switch devices can not only communicate with each other but also provide the third party application server with the interface. In this paper, we firstly illustrated the working principles and main tasks of the SIP-based centralized video conference system. Secondly, the paper analyzed the frame structure of this conference system, including system construction, software structure, security policy, interface standard of protocol and so forth. Moreover, were introduced the crucial technologies of the SIP-based centralized video conference system. Thirdly, the paper designed the general frame structure of video conference platform based-on SIP and the corresponding test cases were complied, which can verify the performance and functions of the system.Fourthly, according to the video conference system model and SIP platform, a distance education system was designed and implemented, and its network topology and distance education frame were also demonstrated. Finally, the paper focused on the further research on the working mechanism of the SIP-based remote-classroom teaching with the basic principle of the session protocol, which can prove the feasibility of the development and application of a SIP-based centralized video conference system once more from the practice of the distance education. |
PDF Full Text Request