Assessing workflow languages for composition of real-time communication services

The programmable network envisioned in the late 1990s within standardization and research for the Intelligent Network is taking another attempt to come into reality using IP- based Next Generation Networks (NGN) and Application Programming Interfaces (API) for open developer access. Adopting technical concepts of providing high-level APIs for open service access from the Internet and World Wide Web (WWW), some major telecommunications operators have started developer portals to allow 3rd party developer access to internal service enablers and network functionality. Composition of services by using these exposed APIs may be realized on multiple layers. We address in this report the composition of services based on orchestration languages and assess those in the context of the execution of real-time communication services. We propose a two-folded composition model for component and workflow driven compositions.