Understanding Multiple-tree-based Overlay Multicast

The two main sources of impairment in overlay multicast systems are packet losses and node churn. Yet, little is known about their effects on the data distribution performance. In this paper we develop an analytical model of a large class of peer-to-peer streaming architectures based on decomposition and non-linear recurrence relations. We analyze the stability properties of these systems using fixed-point analysis. We derive bounds on the probability that nodes in the overlay receive an arbitrary packet of the stream. Based on the model, we explain the effects of the overlay’s size, node heterogeneity, loss correlations and node churn on the overlay’s performance. We show how and under what conditions overlays can benefit from the use of error control solutions, prioritization and taxation schemes. Our findings lead us to the definition of an overlay structure with improved stability properties. Based on our results, we identify the components that are needed to achieve good data distribution performance via overlay multicast.