Today we are faced with an increasing variety of networks and end systems. The resulting heterogenous environment imposes new challenges on communication support for multimedia and collaborative applications. Heterogenous group communication is a key issue for the proper support of such applications. The approach outlined in this paper forms a first step towards an active multicasting network (AMnet) that is capable to provide flexible, scalable and efficient support for heterogenous group communication. RSVP is used as signaling protocol and QoS filters form the active components in the networks nodes. They scale the QoS down to the individual requirements of subgroups or single members within a heterogenous group communication. Therefore, they remove information (e.g., color information) from continuous media streams, such as video streams. The basic architecture and concept as well as a prototype implementation and some measurements are presented in this paper.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.