The latest debate in P2P and overlay multicast systems is whether or not to build trees. The main argument on the anti-tree side is that tree construction is complex, and that trees are fragile. The main counterargument is that non-tree systems have a lot of overhead. In this paper, we argue that you can have it both ways: that one can build multi-tree systems with simple and scalable algorithms, and can still yield fast convergence and robustness.
This paper presents Chunkyspread, a multi-tree, heterogeneous P2P multicast algorithm based on an unstructured overlay. Through simulation, we show that Chunkyspread can control load to within a few percent of a heterogeneous target load, and how this can be traded off for improvements in latency and tit-for-tat incentives.