Upcoming broadband networks offer a bearer service suitable for modern distributed applications. High bandwidth capacity and low transfer delay are two characteristics of such communication services. Beside these performance-oriented parameters, many applications have additional requirements in respect to quality of the used communication service. Computer Supported Cooperative Work, distributed parallel processing and virtual shared memory, for example, depend on error-free data exchange among multiple computer systems. Additional problems occur for the provision of a reliable multipoint service, where errors are more likely and the sender has to deal with numerous receivers. In order to meet the required reliability, powerful and scalable error control mechanisms are essential. Therefore, this paper presents a novel concept, named Local Group Concept (LGC), for large-scale reliable multicast.