Research And Application Of Sigtran In Softswitch

Along with a speedy development of Internet,IP technology has become the most popular technology for development of information network. Also both SoftSwitch system structure and 3G communication system are based on IP-based packet-switch network,it is inevitable to transmit signal between SCN and IP network. SIGTRAN protocols defined by IETF resolve problems caused by signal junctions between two kinds of network.At the beginning of this paper, it discusses essentiality of Signal Gateway in IP network and important status of SIGTAN protocols. In SoftSwitch structure , SIGTRAN is used in Signal Gateway and Media Gateway Controller to transmit traditional telephone signal between them, such as NO.7, ISUP, TUP, DSS1 and so on; and IETF has defined correlative user adapter layers to transmit them in IP network, such as IUA/M3UA/M2UA/M2PA/SUA and so on. Although IETF has defined many user adaptation layers, all of them have the similar structure module. During the second part,the paper concludes the common structure model of SIGTRAN protocols, points out their commonnesses and introduces basic functions of User Adapter layer and Bear layer .This paper focuses on M3UA especially at the third part. From macrostructure and microcosmic layers, several key problems are discussed here: comparing and selecting one of ways to build network; how to realize and configure signal route; messages distribution and analysis about stability and security. At the fourth part,it discusses the project to realize a SG using SIGTRAN from main modules,working principle and work flow. At the end of this chapter it describs realization of SIGTRAN in Media Gateway Controller in brief.At last,the paper discusses the consideration about support to mobility of SIGTRAN, and compare M3UA and SUA here. Because fundamentation of SGITRAN, it must have a wonderful expectation in the future.