The Reserch On Ears Under NGN

Multi-layer is the most important character of NGN. There are several layers, such as access layer, control layer and service layer. Each layer can concentrate on the dedicated task of themselves. Service layer just implement many application service, especially offer a lot of envalued service for the carrier. So the development of service layer absorbs much attention from the carriers.Application Server is the device based on service layer. It is responsible for the generation and management of envalued services. It provides the running environment of application service. Many API are also supported in application server. This builds the base of multi service running in NGN.EARS(Extend Application Routing Server) is a kind of application server. It conducts the softswitch setup the VoIP call in NGN. The most task of EARS includes: make routing decision based on IP, trigger access of service application server, the registration and authentication of SIP user, Network element supervision and monitor. It inherits the call handling concept of PSTN circuit switch. Of course we should consider the character of IP routing when we develop EARS. Because we introduce new development technique and new application platform, the...