NGN's Application-IP Centrex

IP Centrex, is a Centrex service that build in a Soft Switch system. Users in the Centrex can be all kinds of the users in the soft switch domain, such as the common audio service users, multi-service users and so on, but those users that connected with the Soft Switch, such as 2G,3G,PSTN and Other Soft Switch users. With the development of NGN, IP Centrex will be more increasingly wide application in the market.IP Centrex not only can provide to the enterprise the traditional Centrex basic business, but also integrate unified news, conference, voice mail, etc. Moreover, IT can satisfy customer demands, those come from different local branches, such as telephone meeting launched more convenient and effective communications business with existing office system.IP Centrex business control the call through the soft switch and ensure the enterprise communication with existing equipments using the soft switch outstanding interoperability and multi-protocols. The session manager equipment is introduced in the network, which can provide QoS guarantees and FW/NAT across function. This scheme can not only provide the IP Centrex business, and through the unity of business platform provides a big customer business suites, including IP multimedia conference, VPN, wireless voice, Web call center, no.1, Web800, unified news, e-commerce, various business. One IP Centrex business can not only provide the functions of traditional 100% PBX based on WEB, and can also provide the enterprise/personal self-help function, and with Windows software integration, simplified communication mode.First, Research and analysis are conducted from the perspectives of IP Centrex service model, the definition of service, related protocols and service application scenarios in the paper. And then the paper presents module architecture. Special attention is paid on designing the business logic process.Second, the procedure for implementation and test of IP Centrex Server is described. The result proves that the solution to design and implementation of IP Centrex Server fulfills the demands of devices and servers in the network. And the prototype of IP Centrex Server provides a reference for industry product.The final part makes a brief summary of the research work and discusses the improvable areas of the implementation, which will be the future work of the paper.