Research Of Telephone Number Portability Providing In SoftSwitch

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 services with control layer, and also separate control layer with transport layer. Number Portability Service not only meets the needs of the development of future communications system, but also means great profits to commercial users and telecommunication operators. However, the modern telecommunication system can not provide Number Portability Service.This paper starts with the encoding solutions of modern telephone numbers; some solutions for Number Portability Service are also introduced. Shortcomings of these solutions are analyzed. Phone Name Technology derives from the successful application of Domain Name System in the Internet which could support PNS perfectly.This paper gives a design of Phone Name System (PNS) based on research of structure, work flow and resolution principle of Domain Name System (DNS), which includes PNS structure, query algorithms, management and work flows of its modules. In the design, the PNS is made by two parts: PNS Query System (PQS) and PNS Data Base (PDB). Centralized management mode is employed in the PQS; on the other hand, distributed management mode is adopted in the PDB. The author proposes multi-PQS solution in the paper and work flow of multi-PQS is introduced in details. Then the work flow of PNS is presented.The author proposes that in order merge to modern telecommunication network, three phases should be taken. Three phases are presented and based on terminals and core network, and then work flows of each phase are introduced. In the phase one, the paper mainly analyses how to use the facilities that we already have to start phone name calls. In the phase two, with the development of terminals which support PNS, phone name query could be done by terminals. In the phase three, traditional telecommunication concepts are rejected. Peer to Peer (P2P) calls are made based on the route mechanism of Internet network.