Research And Implement On NGN Network Service Layer Based On Parlay API

With the stronger and stronger people's demand for new services, a new framework is required to support development of new services and Softswtich has emerged as the times require. Softswitch is the core technology in NGN network service layer. All kinds of service network, such as PSTN, PLMN, H.323 network, SIP network, could be integrated into a new powerful service network.In order to provide service better, Softswitch has two ways to support application development. One is SIP (Session Initiation Protocol) protocol, which is proposed by IETF organization and another is open programming interface Parlay API(Application Programming Interface), which is proposed by 3 GPP organization.SIP is an extensible and easy to use session call protocol, and Parlay API is one of the most important service development technologies in NGN. Protocol operation details are hidden by the mapping relationship between API and network protocol and service developers could develop kinds of rich and colorful services easily and quickly only by kinds of Parlay API's SCFs (service capability function). They are all so popular that it's significative to do research on the mapping relationship between SIP protocol and Parlay API. Parlay gateway is network device which provides service developer with Parlay API and carry out protocol mapping function. Parlay gateway provides kinds of SCFs, such as call control SCF, UI SCF, user location SCF and so on.In the thesis the Parlay gateway's system structure supporting of SIP is researched, then the SIP protocol's basic principle and operation method are described, lastly the mapping relationship between Parlay...