Research Of CODEC Negotiation System In Soft Switch

NGN(next generation network) was one milestone of the telecommunication history. As an integrated and open network framework, NGN provided voice, data and multimedia. Through optimizing the network structure, NGN not only realized amalgamation of network, and more importantly realized amalgamation of opration so that grouping exchange network could inherit abundant opration function of old circuit exchange network, but also could quickly provide new operations, which could not be supplied by old network in the whole network. NGN'appearance indicated the arrival of the new generation of telecom network.As the embodiment of the separateness idea of operation/control and transmission/access, softswitch was the key technology of NGN system framework.Through realising hardware with software, softswitch realized control, transfer and operation processing functions of old switch; each entity connected and communicationed through normal protocols so as to realize all kinds of complicated protocols more quickly and provide operations more conveniently in NGN. Specifically, softswitch's advantage was that system structure was in focus and clearly and softswitch was convenient to amalgamation and quickly build operations between different networks. Meanwhile, softswitch optimized system structure and had obvious strong QoS management.NGN could provide more abundant operations than PSTN network, and could also realize amalgamation of many networks. So the before CODEC negotiate systerm designed for PSTN could not be adapted to the new operations. We needed restudy consumer's communication and operation's characteristic in NGN environment, and planned better CODEC negotiate systerm seasoned with network development. NGN could provide more abundant operations, took more increment operations and created more profit, so NGN advanced higher demands for CODEC.This paper first introduced NGN's systerm framework, characteristics, functions and its demand for QoS. Next this paper introduced the CODEC function of NGN access media gateway.The main part of the paper was the CODEC technology, and the negotiation process in NGN.