The Research Of The Interworking Between SIP And MGCP Protocol Based On The Softswitch

At prensent,along with scientific and technological progress and incessant advance of demands,traditional telecommunication network which is consisted mainly of voice transmission has been brought tremendous pressure by data services and the rapid development of multimedia services.So the open next generation network architecture which provides voice, images, data integration for multimedia integrated services progressively enters into people's vision and becomes a hot spot in the telecommunication network.The softswitch is the core technology of the next generation network,for it can be the core to offer calling, control and service in the next generation network,and it also plays the key role in the evolvement of SCN to the PSN.The interwoking of ISUP,wireless access,SIP,H.323,MGCP,etc,is the found- ation to realize the core device of the softswitch.This thesis narrates characterisitcs and work mechanism of SIP and MGCP respectively,which goal is to look for their sameness and differentia.Based on analyzing some problems of the interworking protocols conversion,such as seeking address,resource negotiation,authentication and accounting which are brought to the businessman's attention,the paper presents a solution scheme,which is to expand an interworking module within Call Agent and adopts the systematism design in RADIUS Protocol.Call Agent is designed in terms of modularization principle,and its botom is SIP and MGCP protocol stacks,which implements syntax composing and assures the correctness of protocols and messages.The interworking module is set up above the protocol stacks,which takes charge of syntax explaination.Including of building the state of the entity,sending out the directive according to the current state of the entity,etc.In the systematism design of RADIUS,the authentication subsystem adopts encryption arithmetic,the accounting subsystem implements accounting function by collecting the call records and making accounting bills which are sent to the accounting center.The function of authentication and accounting is implemented by systematism and the interworking module introduces module design,which improve the livelong system's efficiency and reliability.