In this paper, we present BAD, an application-level multi- cast infrastructure. BAD is designed to improve the perfor- mance of multicast dissemination trees, under both a static and a dynamic environment, where the eective bandwidth of the network links changes with time. Its main goal is to improve the data rate that end users perceive during a multicast operation. BAD can be used for the creation and management of multicast groups. It can be deployed over any DHT retaining its fundamental advantages of band- width improvement. BAD consists of a suit of algorithms for node joins/leaves, bandwidth distribution to heteroge- neous nodes, tree rearrangement and reduction of overhead. We have implemented BAD within the FreePastry system. We report on the results of a detailed performance evalua- tion which testies for BAD's eciency and low overhead. Specically, our experiments show that the improvement on the minimum bandwidth ranges from 40% to 1400% and the improvement on the average bandwidth ranges from 60% to 250%.