orted by the operators' network. http://en.wikipedia.org/wiki/Service Delivery Platform Service Delivery Platforms The salient components of an SDP are service creation environment, service orchestration environment, service execution environment, and service control and management environment. A number of standard bodies are working to come up with reference architecture for SDP. Examples are open mobile alliance service environment (OSE), Telemanagement Forum's Service Delivery Framework (SDF), Open Service Access (OSA) Parlay, and SO on. Most of these reference designs expose the Telecom capabilities through flexible service-oriented architecture (SOA)-based programming interfaces such as Parlay-X [4]. Recently, Telecom oper- ators are also exposing their capabilities through lightweight mashable interfaces or widgets to compete with the Web 2.0 Internet service providers. One such example is BT Web 21C [5]-a service aggregation environment that enables a user to create Telecom mashup applications very easily. This chapter focuses on two integral aspects of next-generation SDPs-service creation and control infrastructure during service execution. In particular, it cap- tures some of the inherent challenges in effective composition and control of Telecom capabilities for next-generation converged applications, in an open, col- laborative environment-challenges that are inadequately addressed in existing standardized frameworks and protocol specifications. 1.2 Service Composition Framework As mentioned earlier, core Telecom functionalities need to be accessible and com- posable with converged IP services to support the evolving business models. This leads to rapid integration and reuse of these services. Web 2.0-oriented mashup- style applications should also be able to effectively use Telecom functionalities (e.g., call services, SMS, location, etc.) in their application creation environments. To support the basic operations such as voice and SMS, the building blocks of a Telecom infrastructure-location registr