VoIP (Voice over IP) is a rapidly growing area with great market potential. To promote it for both commercial and research purposes, a prototype VoIP system based on state-of-the-art Motorola communication techniques has been developed. It is a gateway system integrating a PBX and a VoIP module. All components that H.323 defines to support VoIP are implemented in the VoIP module, though in a simplified manner. As an embedded system, the system features real timeness and task distributiveness. A number of additional techniques are used to improve the performance, including noise suppression, zero copy, and buffer structure optimization. When refined in interoperability, the system will also readily serve as a product. VoIP (Voice over IP) is a rapidly growing area with great market potential. A promote VoIP system based on state-of-the-art Motorola communication technologies has been developed. It is a gateway System integration a PBX and a VoIP module. All components that H.323 defines to support VoIP are implemented in the VoIP module, though in a simplified manner. As an embedded system, the system features real timeness and task distributiveness. A number of additional技术 are used to improve the performance, including noise suppression, zero copy, and buffer structure optimization. the system will also readily serve as a product.