Research And Realization Of Signalling Gateway With High Reliability In NGN

With the progress of telecommunication technology, PSTN based on circuit switch technology is carrying out the transition to the Next Generation Network (NGN) increasingly. NGN will be an IP network with whole services based on packet switch technology, which will support telephone service, data business and video stream media service, etc. No.7 Siggalling is extensively applied in PSTN and No.7 Signalling Network is one of important telecommunication supporting networks of PSTN. For realizing signalling intercommunion between PSTN and NGN,we need use No.7 Signalling Gateway.Signalling Gateway (SG) is an important function entity in NGN which is a signalling agent at the edge of No.7 Signalling Network and IP network to receive and transmit signalling messages. It is used to relay, translate and end signalling messages. Firstly, the author analyses developmental process of the telecommunication network and studies signalling gateway technology for realizing communication and amalgamation between NGN and PSTN. The author considers that present research contents of SG include: realizing interconnection and intercommunication of varied networks,effective integration with present Common Signalling System,realizing signalling transfer with high quality in IP network, and lower management cost of signalling networks in NGN,etc. Secondly, several key technologies of realizing SG are researched. The paper introduces protocols correlated with Signalling Gateway, including No.7 Signalling protocols,SIGTRAN protocols cluster; Compares two communication mechanisms between No.7 Signalling Gateway and IP network, discusses choosing standards of various communication mechanisms; following, researches messages routing mechanism in SG and credible transfer of signalling messages in IP network. Subsequently, the author produces a material SG design scheme with high reliability which applies M3UA protocol, adopts distributed modularization design, and takes manifold measures to ensure system with high reliability. The paper intrduces hardware system designs and software system designs in detail, analyses organizing networks ability of the SG, and discusses various strategies which realize Signalling Gateway with high reliability detailedly. Finally, according to the design scheme, the paper introduces material implement details of SG based on VxWorks OS with high reliability, focusing on the realization of software system. In the end, test project and test result are presented.