Research And Test Of Application Layer Protocol Of IMS

With the development of 3G,communication systems don't just provide the traditional phone which offer voice,but also need to provide a way can communicate with data and multimedia.In R5, 3GGP offer a design of the core net for NGN,that's IMS.IMS is founded on all-ip,which can deal with kinds of IP multimedia service and control the flow of the complicated call.IMS has the three features of NGN .First, service and control are separate,control and bearing are separate.Second, the structure is layered, inside of which is also separated.Last, the protocol is unified.The application layer protocols of IMS mainly are SIP and Diameter.SIP is used for calling and controlling of service.Diameter is used for AAA.IMS is the important phase of the net development.It's necessary to do the coherence testing of protocol which used to check whether the developed net entity is consistent with the protocol.In practical,the earlier finding bugs in research edition,the less cost will pay for correction and maintenance. So it's useful and necessary to realize a protocal testing tool aimed at application layer protocol of IMS which is used in system testing to check whether the developed net entity is consistent with the protocol.The research in the article includes analyse the designing of IMS,deep research of application layer protocol Sip and Diameter.Basing on those research and the work in company ,realize the achievement of the protocal testing tool aimed at application layer protocol of IMS.In practice testing work,by using this tool discovered many bugs of the net entity of IMS.This tool has well effect in practice.