The Research&Design Of Parlay Based Value-added Services In NGN

Next Generation Network (NGN) has a good level structure, which is divided into four independent layers, including network service layer, control layer, transport layer and access layer. separate service with control layer, and also separate control layer with transport layer. NGN use open API interface for service development, make service developing independent from under-network. And service layer become an open public platform, not only to promote networks for service separation integration, but also allows service providers to concentrate on service development, create various value-added services.Parlay/OSA is developed by Parlay Group, issued by the European Telecommunications Standards Committee (ETSI) for open service programming interface (API). Parlay/OSA includes Parlay Gateway, Parlay application servers, and a series of standard interfaces between them (Parlay APIs). Parlay Gateway can communicate with under-network by different protocols, shield complexity of the under-network and through a variety of Parlay APIs to open network capacity for high-level application servers. Thus, a third party can develop service without under-network details. This paper focuses on how to use Parlay APIs to develop value-added services.Firstly, this paper introduces Parlay structure and Parlay's position in NGN, study characteristics of functional entities including Parlay application servers, Parlay gateway servers, Parlay framework, summarizes APIs between App, gateway, and framework.To provide application server network resources by a unified API, Parlay needs to communicate with network functional entities with different protocols, such as communicating with the GSM SSP by Cap protocol (Camel Application Part), communicating with Soft Switch in IP network by SIP protocol, SNMP protocol. After the detailed comparative study of Parlay, SNMP, CAP, Parlay, get translation from Parlay to SNMP protocol, and translation from Parlay to CAP protocol.Then, this paper introduces several Parlay based value-added services, including iNumber, Q-Box, PHS Hiring, Web conference. Finally, take Q-Box service as an example, detail Q-Box service processes, discuss the use of Parlay to realize Q-Box service, provide service redundancy design to ensure service system reliable, and give the performance test results.