This paper focuses on the application control functionality required for future interactive multi-user, multimedia applications. Accordingly a new service control reference model is described which is part of a more general Multimedia Reference Model. This service control reference model introduces application building blocks that facilitate application creation and management in all kinds of multi-user, multi-point and multi-channel environments in interactive video and other multimedia broadband networks. The Multimedia Reference Model is derived by applying the conceptual modelling technique standardized for Intelligent Networks by ITU-T. Based on the service control reference model, a distributed functional architecture is developed which contains -among others -the functionality for application control, session management, and security handling. The functional design of the architecture enables it to be mapped in various ways onto the physical network components, for example, in a set-top box/ video server configuration. The new Multimedia Reference Model is applied to an interactive multi-user video games environment.