Design And Implementation Of Single-line Ip Telephone Gateway

The IP phone techonology, which uses IP network instead of expensive traditional long distance trunk, greatly reduces the cost of long distance commication and has enormous commercial potency. As a important part of VoIP network, IP phone gateways are usually produced on PC platform, router platform or switch platform and may have high average channel cost, less flexibility and inadequate QoS. The developed IC and SOC techonologies allow SCM and DSP to be integrated on a single chip. Accordingly on the SCM platform, we can develop the single channel IP phone gateway, which may overcome the defects referred above.In this paper, I firstly introduce the IP phone techonology and ralated protocols. Next I analyze the work process of IP phone gateway in VoIP network and compare all kinds of existent IP phone gateway solutions. After that, I put forward the SCM platform based develop solution of the single channel IP phone gateway and discribe the develop hardware platform, software platform and compile tools. I also design the applications software and divide it into several different modules. Then I particularly introduce the design and realization of the mainly control module, interrupt dispose module, SDRAM driver module, nework task dispose module, address transfer module, phone task dispose module and other peripheral equipment driver module. Finally, I present the test result of the experiment software, and give some idea about the work in the future.