service feature enables the application to find out which network service capability features are provided by the service capability servers. The registration support service enables a service capability feature (e.g. user location) to register its existence. The discovery support service enables applications (end-user services) to identify all the service capability features that have been registered in a service capability server. 9.6.5 APPLICATION SERVICES Application services (end-user services), for example VPN, conferencing, and location- based applications, are implemented in one or more application servers. The end-user service is provided by executing the service logic on the application server. Service logic and data for end-user services reside on the application server. Application control servers provide the control for the application and application con- tent servers provide the content for the application (e.g. text, video clips etc.) 9.6.6 SUMMARY The overall architecture SO far can be presented as a stack. See Figure 9.7. 9.6.7 THE WAP/MExE/SAT LAYER The physical enablers are sometimes considered not to be SCS. Therefore they are treated as a separate layer here. The name service enabler is still correct. Two important enablers Understanding Changing Telecommunications - Building a Successful Telecom Business Applications executing on an Application Application Application application server objects objects objects communicate via OSA API with framework and service Client Client Client capability servers application A application B application C The framework cares for Service Service Event Integrity authentication/authorization subscription discovery notification management of applications. Additionally SC servers can Authorization register their SC features Authentication Service registration User interation Connectivity Call control Mobility messaging management Service capability servers Generic Connectivity provide SC features (= bundle call control Generic status manager of interface class