Design And Implementation Of H.323-based Voip Terminal

Because of various benefits, such as low price, high efficiency of using network, etc., VoIP has becme one of the services that grow at the fastest speed in telecommunication industry.H323 is one of important protocols of VoIP, and is the most mature technological VoIP standard, and is the most common applied VoIP standard.H.323 protocol defines four main components: terminal, gateway, gatekeeper, and MCUs. Terminal is an important part of H.323/VoIP system, it offers users the function of voice telecommunication and others. There are two main technologic implements of VoIP terminal: based on PC and based on hardware Phone. And the most are based PC, The purpose of the project group that the author participated is to aim at low layer market,and to work out a VoIP terminal that is high performance/price and easy to use based on H.323, It is a embedded system based hardware Phone. After working hard to combine H.323 protocol with PA1688 embedded chip,we successfully developed out KE1000. KE1000 provides the basic functions that be defined by H.323 and simple and convenient operating and management functions, so it makes good winning after entering market.The author writes this article based on the project,and he first introduces embedded system's architecture,development environment and design technology, including design metric's influence on embedded system's design. secondly introduces the architecture,protocols stack and call procedure of H.323. then introduces KE1000's design and implement, including mapping functions into hardware and software, hardware's architecture design, software's architecture design, and hardware's distribution, as well as introducing the functions of hardware modules and software modules. Then introduces KE1000's tests. eventually, the author makes a summary of KE1000 and puts forward some advanced ideas for it.