to dis- cover a service interface previously registered by the provider. As such, the service broker is essentially a clearing house for service interfaces. In addition, the service broker may effectively act as a secure boundary that allows the domain owner to provide controlled access to internal services. In some cases, the service broker can also serve as a messaging broker and route messages to different services. Service orchestration: Service orchestration is a centralized mechanism that describes how diverse services can interact. This interaction includes message exchange, business logics, and order of execution. Service orchestration intro- duces state and flow control to create dynamic relationships between services that are determined at runtime, rather than the construction phase. A busi- ness process specifies the potential execution order of operations from a collection of services, the data shared between these services, which partners are involved and how they are involved in the business process, joint exception handling for collections of services, and other issues involving how multiple services and organizations participate. Breaking the opaqueness of diverse services means specifying constraints on how the operations of collections of services and their joint behavior can be used. The description of the sequence of activities that make up a business process is given by service orchestration. Rules provide a powerful business logic representation in many modern information systems. Built-in integration for rule engine support separates orchestration logic from business policy and reduces the effort of adapting to changing business needs. 9.5 Conclusions In this chapter, we presented an IMS-based testbed designed to provide a platform for research in real-time services integration and orchestration. The components used within the testbed were developed based on open-source software. SIP-based service orchestration module is reported and discussed along with service-oriented system functionalit