The Design And Implementation Of VoIP Software System Based On Linux

Design and implementation of VoIP software system based on embedded Linux is the goal of the thesis. In the system, HI3510 ARM9 and DSP dual-core processors and embedded Linux operating system are used. Basic voice based on IP and other business needs are implemented through powerful computing capacity of common embedded processing chips, interface expansion and the development of corresponding software modules in the platform.In the thesis a new software frame method is put forward for loss or delay of audio data、video data and other data. In the method, data is buffer processed while receiving and sending data to raise the transmission speed and accuracy of data.Modular design is adopted in the software system frame. Based on the need of the system, the system consists of three modules. They are GUI module, Signal/Controller module and protocol layer module. GUI module is the application layer module; Protocol layer module consists of SIP protocol module, H.323 protocol module and RTP/RTCP protocol module. Main functions of SIP and H.323 protocol are establishment of calling and consultation, RTP/RTCP protocol realizes the function of media data transmission; Signal/Controller module realizes the interface unification and control establishment of calling.Five parts of works are consisted in the thesis: design and implement of voice terminal; the interface design between application layer and protocol layer, the interface design between application layer and driver layer; the design thought of application layer, the internation of application modules, and the design and implementation of every application module; the design of GUI in the MiniGUI graph system; the test of the software system. The designed VoIP has implemented audio and video functions, the practice has proved that the method is a better VoIP method.