Research And Implementation On H.323 Gatekeeper Of Address Translation And Routing Management

With the development of Internet and communication technologies, the telephone service over IP-based network has become the mainstream of the telecommunication network. VoIP technology is going through unprecedented development. All sorts of VoIP products stream to market and this changes people's life style. Meanwhile, VoIP protocols and standards, the currently researching hotspots, are continuously renovated. Comparing with other standards, the most advantage of H.323 is its maturity and highest market share. With the development of VoIP technology, H.323 is assimilating advantages of other relevant standards, making self-improvement, becoming more mature and sturdy. H.323 gatekeeper acts as an administrator role in H.323 network. It stands on the upper layer in the whole network, and manages all enpoints and calls located in its zone. The mainly functions for H.323 gatekeeper are: Endpoint Address translation, Access control, Bandwidth management , Zone management and Routing management. It is impossible to construct a steady H.323 Network without gatekeeper.Firstly, this paper summarize the basic theory of IP Telephony and the structure of H.323 system, It thoroughly researchs the main functions of IP Telephony gatekeeper system and its work flow so as to design the whole structure of gatekeeper system. Then, it fully analyses the Address translation and Routing management technology, sums up the problems occurring during their implementation and brings up relevant solution. Lastly, it designs the module of Address translation and Routing management.By studying the Address translation and Routing management technology in detail, this paper sums up the shortages of Address translation and Routing management at present:(1)Low efficiently of Address map table, the long time of address translation, limitation of resolution ability and expansibility, all these influence the successful call rate in unit time.(2)Call-establishment between domains is implemented by gatekeeper, but the imperfectness of call-fashion and standard causes the problem of interwoking address between domains.(3)With the rapid increase of gateway, it becomes more difficulty to maintenan and manipulate gateway, gateway routing is one of the most difficult problems.The thesis proposes a plan of settlement scheme for the above problem in IP Telephony network with H.323 standard. The scheme is capable of affording real-time and convenient Address translation and Routing management for gatekeepers between...