Date Added: Jan 2013
In the development of VOIP technology, applications of real-time voice communication has corner into widespread use over the Internet. However, their over reliance on PC environment restricts the applying fields of most VOIP software, and embedded VOIP is one of these blind spots. The VOIP application in this paper sets the hardware foundation on ARM9 embedded platform, adopts SIP and RTP as the transmission protocol and employs CELP compression algorithms to ensure the low-latency and high quality communication. In addition, Linux operating system and ALSA device driver are used to meet the needs of cost control and sound effects. Viewed from the experimental results, the VOIP system proves to be successful in both its real time voice communication.