A Research Of VoIP Based On The Embedded System

This design uses SAMSUNG Corporation's S3C2440 processor and Linux separately as system's hardware and software development platform, introduces an application solution of VoIP gateway, and Chooses legerity's advanced SLIC and CODEC voice chip Le77D11 and Le78D11 as the voice input system of VoIP .Firstly, by analyzing the function requirement of the VoIP and synthetically considering the factor of function, speed, volume, reliability and so on, this thesis selects the S3C2440 processor of SAMSUNG as the hardcore based on which the peripheral hardware structure is designed, the main peripheral devices include data storage devices, RS-232 serial port, USB, power supply circuit, DM9000 network interface, Le78D11/Le77D11,touch panel, PS/2 keyboard, etc. On which the hardware development environment is based; Software development environment includes the installation of PC Linux, the usage of VMware virtual machine, the installation of cross compiler tools, the compiler and download of the zImage, writing Linux device driver, debugging application, and so on.Secondly, this article evaluates the principle and classification of the codec technology, and makes analysis on and comparison of the performance of several common codec algorithms, finally chooses the G.723.1 standard, enable it runs in the development board. After being optimized through algorithm procedures, the G723.1 running rate greatly enhanced. The network transport of PC and VoIP has been completed, MiniGUI development environment is established and the simple interface of VoIP is designed.