Designing For Gatekeeper Software Of IP Telephone In HFC Network

With the increasing demands of bandwidth and the development of "the three nets in one", video, voice and data services are unified for one network platform. HFC network has the tendency of being broadband integrated service one. We put forward a new topic concerning how to provide IP phone services in new HFC network. Based on new HFC Network, this thesis is to design and realize gatekeeper software of IP telephone.In order to adapt narrow network bandwidth, data compress should be performed in commonly used IP phones; therefore, it is difficult and high-priced. Whereas new HFC network has the advantage of bandwidth and cost, consequently, it is desired to behave more and more perfectly on "the last kilometer" of information superhighway. The IP phone in new HFC network whose datum need not to be compressed has an advantage over present IP phone. Gatekeeper is a software entity that (?)nages communication services between gateways. As a result of speciality of new HFC network, it is significant to design and realize the gatekeeper software when IP phone services are performed.In this thesis, relevant IP phone protocols are analyzed and compared. Then a conclusion is drawn that H.323 is more mature and widely used. Our country selects H.323 as IP phones standards, so does the gatekeeper software in this thesis. Then relevant protocols of gatekeeper are researched in detail, including function characteristics, structures and communication control process.The emphasis of this thesis is design and realization of the gatekeeper software. Firstly, the author makes a general requirement analysis. The gatekeeper software is designed according to 4th version of H.323, but connectivity with other H.323 devices is also required. The functions specified in H.323 are implemented such as address resolution, call access, zone management, call management and bandwidth control. Besides, we should satisfy customer requirements, e.g. web management, dynamic modification of running parameters, supporting NAT environment, applying Radius protocol to authentication and account function. Secondly, According to the...