H.32协议及其扩展在语音网关上的设计与实现.docx

DESIGN DESIGN AND IMPLEMENT2订IoN OF THE MODULE H．323 AND ITS EXTENSIoN oN VoICE GATEⅥ，AY ABSTRAC T With the fast development of IP technology,the appearance of VolP technology has aroused wide attention of world．It is simply understand technology which is replace PSTN to transmit voice by internet，its the most advantage is that widely using intemet environment to interconnect with IP of global，it provides more and better services than traditional services．During the 1 0 years，the bloom of VolP product has been in the market，VolP technology becomes of the most popular topic in computer and telecommunication field．H．323 is the most important and the most influential protocol which was adopted first in the world．H．323 protocol adopts traditional mode of telephone signal，and its character includes delamination，master and slave，centralized control，the multimedia products and applications of various manufacturers be co-operation，laSerS do not have to consider the compatibility issues either,SO the IP network will easy to unite with traditional PSTN if its architecture is base H，323 protocol，H．323 is considered the key technology in the Next Generation Network technology． Voice Gateway is node which access the IP network to the PSTN，it is a important role in the VoIP architecture．Voice gateway have low·cost，high cost—effective character,if using the Voice gateway Call make internal communications costs near zero and external communications costs also decreased by 40％to 60％．With the maturity of VolP technology,Voice Gateway has been able to access to more different network，further to improving the communication with sorts of PSTN protocol，the transform of video／audio code，and let operators use more new supplementary service which iS base on IP network． This paper is to illustrate the design and implementation of the H．323 protocol and its extension，with the project experience which the author participated in—-The Development of Vanlink Voice Gateway．The first paragraph of