The Research Of NGN Deployment Project Based On Softswitch

IN (Intelligent Network) technology provides a running mode for voice-exchanging by dividing service information from control information. And by the IN technology many value-added services are provided, such as 800 Service, Billing Card, and Grade Searching. However there are still some inherent limitations, which have been a great problem and obstruct the development of value-added services. For example, service-developing and operation is in a close environment, SCP is in concentrated control, services is binding with certain bearing network, and services have low capability on customization. Meanwhile, characterized by openness, distribution and integration, the Next Generation Networks (NGN) will deeply change the concepts and architectures of traditional telecom network, and Softswitch is the extension of the voice network in NGN systems.Trial networks based on Softswitch technology are being built by some telecom operators in recent years. Some of them even built the backbone network in nation-level, and a part of services are deployed on application layer step by step. Based on the research on the protocols and network system of Softswitch network, this thesis analyzes the Softswitch network deployment project of ShanDong CNC in detail, and proposes a methodology of this project.Firstly, the paper depicts the history and system structure of the NGN and discusses the system structure and main equipments of the Softswitch, interfaces and SIP protocols, calling flow and interconnection control flow with other networks. Secondly, according to the facts of few custom and currency, the construction mode select and relative setup principles are analyzed and ascertained, and the paper proposes a solution dredging the long-distance Softswitch service, which applies MPLS VPN as the local bearing to carry Softswitch service and striding-field VPN to interconnect with backbone IP bearing network. The paper also shows the testing results. Lastly, according to the testing results, the paper gives some advices on the Softswitch network deployment project of Shan Dong CNC.