A Design Based On The H.323 Voip Gateway Software

Audio communication by internet is very complicated as a system, project which has been used in a widely ranges, and many technology has been used including VoIP (Voice over IP) which is the most basic technology. The called VoIP is packetisation and transport of classic public switched telephone system audio over an IP network .The analog audio steam is encoding in a digital format, with possible compression, and encapsulating it in IP for transport over your LAN/WAN or the public internet.H.323 protocol has been suggested by ITU-T 16^th group since 1997 . It is consist by a group of protocol including some is used to encode and decode and packet audio signal and video signal ,some is used to accept and send control signal order, others is used to capacity exchange .four components is defined to consist communication system based network in H.323 such as terminals, Gateways, Gatekeepers, MCs and MCUs..The Gateway shall provide the appropriate translation between transmission formats (for example H.225.0 to/from H.221) and between communications procedures (for example H.245 to/from H.242). This translation is specified in Recommendation H.246. The Gateway shall also perform call setup and clearing on both the network side and the SCN side. In general, the purpose of the Gateway (when not operating as an MCU) is to reflect the characteristics of a network endpoint to an SCN endpoint, and the reverse, in a transparent fashion.In this thesis an audio gateway based on H.323 protocol is analyzed as blueprint and defined models classify and interfaces between models, then understand whole VoIP system and improve some lacks of H.323 in application.The first chapter overviews the H.323 protocol system construction. Chapter two shows the summary design. Chapter four illustrates the model classify and chapter five outlines its interface details. Then chapter six discusses the process and the results. Finally chapter seven means the whole work...