Strategyproof Mechanisms for Dynamic Multicast Tree Formation in Overlay Networks

In overlay multicast, every end host forwards multicast data to other end hosts in order to disseminate data. However, this cooperative behavior cannot be taken for granted, since each overlay node is now an intelligent end host, rather than an obedient router as in IP multicast. Ideally, a strategyproof mechanism should be provided to motivate cooperations among overlay nodes so that a mutually beneficial multicast tree topology results. In this paper, we apply mechanism design to the overlay multicast problem. We model the overlay network using the two scenarios of filled and unfilled buffer, and further design distributed algorithms that motivate each node towards a better multicast tree. Since network parameters and constraints change dynamically in reality, our protocol dynamically adapts to form a better multicast tree. The correctness and performance of each distributed algorithm are verified by extensive implementation results on PlanetLab.