Addressing Heterogeneity, Scalability, and Privacy in Layered Multicast Congestion Control

Multicast is attracting a resurgence of interest because it has a potential to address the explosively growing need for efficient streaming of large-volume Internet content. However, to realize the potential, large-scale multicast distribution requires effective congestion control. In this paper, we design SIM, a protocol that combines three distinct mechanisms (Selective participation, Intra-group transmission adjustment, and Menu adaptation) to provide a general solution for efficient fair scalable privacy-preserving multicast congestion control with heterogeneous receivers. Whereas the individual mechanisms have appeared in earlier multicast protocols, our main contribution lies in the cohesive integration of the techniques. SIM achieves such integration by operating the three mechanisms at different timescales and distributing the responsibility for control to different entities in the network. Besides, to instantiate and integrate the three control mechanisms, SIM employs several novel techniques of independent interest. Our extensive evaluation confirms the salient properties of SIM in diverse settings where receiving capabilities are highly heterogeneous, bottleneck capacities fluctuate, bottlenecks migrate, and session membership is dynamic.