Earticle

Through analysis of mechanism and characteristics of Session initiation protocol (short for SIP), it is found that SIP possesses prominent flexibility and expansibility, which meet the requirement of Internet infrastructure and media flow transmission. To some extent, tight-coupling model based on SIP reflects the fundamentals of distance education and session initiation. Furthermore, while key control and media mixer are functionally separated. A Web server is added to improve mutual communication. The model SIP-based distance education system with three centralized servers are constructed and the corresponding topology structure is proposed. The mechanism and education function of the model are embodied and realized through several aspects, such as distance class creation, participation and termination, state information notification and education resource control.