Based On The H.248 Protocol Media Gateway Design And Realization

For years, many different data networking protocols have existed,but now,data communications has firmly found its home in the form of IP,the Internet Protocol.On ther other hand,even since telecommunication began,voice communication has rigidly stuck to a classic circuit switched networking environment. In the packet based network,softswitch set up connection in different networks through Media Gateway, NGN can provide voice,data and multimedia services.As the media control protocol in softswitch, H.248 has inherited all advantagesof the protocols before. So H.248 protocol implements the powerful description function, provides more support to application layer and has beter control to media bearer, including media resources and bearer resources. As a popular protocol in softswich, H.248 protocol will have more important efect in next generation network.This paper focuses on the realization technology of media gateway. After analyzing the key technology of the media gateway, the system architecture of the Alcatel 7515 media gateway are introduced. The implemention of the H.248 protocol is the emphasis of this paper. Furthermore, some H.248 applications are discussed such as Caller ID Name Display business and Hearbeat information between Media Gateway Controller and Media Gateway. At last, the test cases are listed. The test results show the device reaches the design objective.The main contributions are as follows:1. The key technologies are studied and summarized in this paper, include voice processing, Quality of service and communications with the soft switch.2. Based on the requirement of the product Alcatel7515, a H.248 application software are designed and implemented.3. Two business applications"Caller ID name display"and"Heartbeat"are studied under the control of softswitch.