Abstract Within the Dutch project Platinum an advanced signalling infrastructure has been developed and implemented. This infrastructure is based o the results of the RACE MAGIC project. It allows users to start up and manage multimedia calls between multiple parties and can be configured to the specific needs of users. Platinum also defines and implements a framework of component applications on top of this infraestructure. The strenght of this framework is its flexibility to combine component applications into groupware applications stisfying the specific needs of a group of end-users. In this paper, we present a part of the software architecture of this framework. It addesses audio and video exchange, conference management, floor-control of media, templates containing the roles of users, and retrieval of information necessary for displaying the human computer interfaces. The paper also demostrates the flexibility of the advanced signalling infrastructure.