Bandwidth allocation policies for unicast and multicast flows

Abstract

Using multicast delivery to multiple receivers reduces the aggregate bandwidth required from the network compared to using unicast delivery to each receiver. To encourage the use of multicast delivery, a higher amount of bandwidth should be allocated to a multicast row as compared to a unicast row that share the same bottleneck, but without starving the unicast flow. We investigate three bandwidth allocation policies for multicast flows and evaluate their impact on the bandwidth received by the individual receivers. The policy that allocates the available bandwidth as a logarithmic function of the number of receivers downstream of the bottleneck achieves the best trade-off between maximizing the receiver satisfaction and keeping fairness high.