Voice Gateways And Design

There has been unprecedented progress in VoIP technologies in recent years, and many telecom service providers have investigated in projects related with VoIP technologies. Their purpose is to transmit tranditional analog voice signal via current IP-centric networks, because of the convenience and economy of networks. Among the majority of their implementation, the voice Gateway plays a very important role. It transforms the PSTN data frame format into IP packet format, and it also translates the switch signaling and protocols. The commercial IP phone network is composed of IP phone Gateway, Gatekeeper, supporting system, telephone network and IP network. The telephone network can be interoperated with IP network by the Gateway, Gatekeeper and supporting system in the commercial IP network archietecture. Meanwhile, the architecture utilizes the IP resource with the highest efficiency and implements the interoperability of traditional telephone business between the two different kinds of network structures, on the IP network's predominance in the technology and economic fields. In the dissertation, the designing and implementation of the voice Gateway based on H.323 protocol are discussed. In the first of the dissertation, the background and development history of VoIP are summed up, and the principle and key technology of VoIP are introduced, while the functions that Gateway shoud have and the standards that Gateway should stand by are expatiated. According to these, the project is provided, then the implementation waies, the problems in implementation and the solutions are discussed. In the following part, based on the hardware designing, the theory of virtual TSI and the theory of continuous machine test are introduced in detail. In the final part of the dissertation, the designing of a voice Gateway driver and a continuous machine test program is presented. The major data structures in the driver program are introduced in detail, so are the designing and implementation of the continuous machine test program.