Reuse of services between different domains using state machine mapping techniques

Abstract

In an Internet protocol (IP)-based multimedia system having a voice over packet infrastructure call handling involves the execution of a call processing program that controls state transitions in a finite state machine termed the “call model.” These transitions are representative of the events that occur during the lifetime of the call and result in the execution of pre-defined actions. In order to provide high level Intelligent Network (IN) capabilities to IP end-point subscribers, a call model layer implements the IN call model, but is closely integrated with the IP-based, multimedia call model that runs within the base platform. The integration employs a precisely defined state-level map between states in the IN call model and the corresponding states in the base call model. The IN call model layer is thus able to support access to IN components to permit the existing base of IN services to be easily accessed and to permit the base layer to support client-level interaction and event handling. A call state information is shared between the two layers to enable them to operate in synchrony. State transitions made by one call model finite state machine (FSM) are thus reflected in the other. Services within the IP space may still be accessed by the base call model layer, allowing for access to both IP-based and IN-based services. The IN call model layer can be reused across various base platforms with little, if any, modification making it essentially portable.