Based Sip Voice Gateway Design And Realization

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.The voice gateway based on ARM chip and VxWorks5.5 realtime system researched in this thesis is an embedded system based on 32-bit ARM microprocessor S3C4510B produced by Samsung. At first, the hardware system taking S3C4510B as the core was built. And then we programmed booloader and ported the realtime VxWorks5.5 OS to the hardware system. After that, the superstratum application software was designed to implement all kinds of function of Gateway.The design of voice gateway includes two parts: hardware and software. The design, implementation and function of the system are presented in this dissertation. The design and implementation scheme of each section was presented in detail in this dissertation. And analysis the design and implement process of each special modul of voice board, including DTMF, fake load, detecting ring current and so on; design and imitation of CPLD control part; write and debug SPI drive program; some feasible methods are provided to improve the perfomance of the system and the timbre,such as zero-copy,throw off dither, analysis and choice of voice decode protocol. After that, author gives the process and result of debugging and testing. At last, a sum-up and an advanced system of voice gateway is prospected in this article.