Distrust and Privacy: Axioms for Multicast Congestion Control

Existing multicast control algorithms typically assume trust and free sharing of information among receivers. We believe that this is not tenable in the long term. We examine multicast congestion control under the constraints of distrust and privacy among receivers. We claim that despite these constraints, large-scale multicast congestion control in a heterogeneous environment is feasible. We discuss three classes of solutions for the multicast congestion control problem, called per-group feedback, selective participation and menu-adaptation. For each class, we identify the limitations imposed by receiver distrust and privacy, and we argue that only a solution that integrates elements of each class can scale and adapt to heterogeneity in network and receiver characteristics. We outline such an integrated solution.