The Software Design Of The VoIP Voice Module

The hardware of "VoIP communication system" consists of the voice module and amanagement PC. The voice module is a VoIP card, in which are stacked four blocksInfineon VINETIC-2CPE EDSP voice processing chips. Each VINETIC-2CPE chipsupports 2-way telephone channels, and the VoIP card can support 8-way telephonechannels. The main function of the management PC is managing multiple voicemodules. The software of the VoIP voice module can realize that the management PCcontrols voice modules, also implement voice communication in internal card andbetween cards.This thesis aimed at the demand of communication between two lines of an internalchip, chips of an internal card, cards, Management PC and cards , brings forward theself-defined communication protocol that implements the function of voicecommunication and controlling. The protocol is implemented in kernel module underMonta Vista Linux kernel mode. Through modifying the kernel source code of MontaVista Linux and the driver of network card, it provides system call based on the driverof network. Meanwhile, callback function is defined in kernel module. After modifyinginterrupt service routine (short for ISR) of VINETIC-2CPE,callback function is calledin ISR. Thereby, callback function and selfdefined system call can work alternately,and implement the function of detecting offhook, detecting dial-up and disposing voicedata, which demands real-time strongly. It improves the performance of system. Thespecial scheme has been successfully implemented. And relevant research results havebeen applied to specific engineering practice.