Expansion Based On The H.323 Gatekeeper System And Its Functions

Making telephone calls by conventional means consists in a process of establishing and disengaging of connections, which involves coordinating signals. The IP telephone system works in the same vein. Its working procedure is accompanied by a set of signals designated as protocols which target at searching a callee, establishing a connection and sending data within bilateral processing capacity. H.323, a VoIP communication protocol which develops from TCP/IP-based technology and which features exchange of video, audio and signals, provides fine solutions to such problems as the control of session calls, multimedia, bandwidth in "peer-to-peer" or "multi-peer" video conferences.The present thesis makes an elaboration on the designing and building-up of a H.323-based Gatekeeper.The first chapter begins with a general introduction to the developing background of the system. It lays out the basic concept VoIP and analyzes its causation.The second chapter puts forward the H.323 Protocol, briefing on its communication procedure, system structure as well as all different types of communication signals.The third chapter presents a classification of the modules in H.323 Protocol-based Gatekeeper and goes on to cover the respective functions of the Gatekeeper, charging and managing console.The fourth chapter expatiates on individual development of the module with illustrations of its flow chart, the basic communication structures, and the codes concerned.The fifth chapter concludes with a summary of the present work, providing insights for the future.