Application Research On Some Key Techniques Of Soft-Switch

The Soft-Switch is the key technology of Next Generation Network (NGN). SIP which is an important control protocol over application layer of Soft-Switch is used to call, revise and stop the multimedia conversation, presenting the advantage of simplicity, flexibility and good expansibility. In the evolution process of NGN, Soft-Switch of core devices shall be compatible with traditional circuit switch network and IP telephony network based on H.323 protocol.Definition, characteristics and main function of Soft-Switch are analyzed in detail. The structure and the signal format of SIP protocol and H.323 protocol are studied primarily and then a series of teaching experiment using the platform with Soft Switch equipment (SoftX3000) and Integrate Access Devices are explored. The transmission process of protocol signal is simulated and analyzed on the experiment platform. The simulation rusult which display the message content and message exchange sequence during a session deepen the comprehension of soft exchange process and correlative protocol for students. The results show the validity and credibility of the design for the platform and Soft-Switch protocol experiment which also satisfy the practical requirement.