 (ITU) [7] and the European Telecommunications Standards Institute (ETSI) [8] are also involved in the IMS standardization efforts. We aim to build our testbed on the principle of Service-Oriented Architecture (SOA), with an emphasis for real-time network services. SOA is an architectural style that guides all aspects of creating and using business processes packaged as services throughout their lifecycle, as well as defining and provisioning the IT infrastructure that allows different applications to exchange data and participate in business processes, regardless of the operating systems or programming languages underlying those applications. A number of SOA platforms and Web-based solu- tions are focused mainly on business process issues. For our development work, we need a platform on which an assortment of experimental tools and products may be deployed and allowed to interact in real-time, thus, allowing for rigorous, transparent, and replicable testing to be achieved. For our testbed platform, IMS technology is applied to form the core network. 9.2 IMS-Based Testbed A system overview of our IMS-based testbed is shown in Figure 9.1, and a more detailed description of the testbed components, especially, of a service orchestra- tion module and its application, was presented in [9]. At the core of this testbed is the "Open IMS Core" from Fraunhofer Institute FOKUS, Germany [10]. The underlying physical network is an Optical Ethernet network with Ethernet Passive Optical Network (EPON) access technology [11] and WiFi wireless network. The Optical Network Control and Management Plane [12] is the network-specific interface to reconfigure the optical network and provision bandwidth with the ability to support carrier-grade Ethernet transport services, for example, QoS (Quality of Service). 9.2.1 Open IMS Core The Open IMS Core project of the Fraunhofer Institute FOKUS was officially launched in November 2006. The Open IMS Core is an open-source implementa- tion of 3GPP's IMS standard. It consists of Call Session Co