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 testies for BAD's eciency and low overhead.
Specically, 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