Functional components for multimedia services

Taking into consideration the introduction of public asynchronous transfer mode (ATM)-based broadband networks, new implementation issues of two multimedia services are presented, i.e., a desktop videoconference service and a messaging service with multimedia extensions. Both of them consist of clearly defined functional components. The communications relationships between these components is analyzed and some quality-of-service requirements are given. Special emphasis is placed on the distribution across the network, i.e., which functional components are located at the users´ side and which parts in (or at) the network