Overlay networks support a wide range of peer-to-peer media streaming applications on the Internet. The user experience of such applications is affected by the churn resilience of the system. When peers disconnect from the system, streamed data may be delayed or lost due to missing links in the overlay topology. In this paper, we explore a proactive strategy that constructs a churn-aware overlay network that reduces the potential of future disruptions caused by churn events.
We describe Chams, a middleware solution for overlay network construction that mitigates the impact of churn. Chams uses a hybrid approach that implicitly defines an overlay topology using a gossip-style mechanism that takes the reliability of peers into account. Unlike existing solutions for reliable overlay construction, Chams supports a variety of topologies used in media streaming systems, such as trees, multi-trees and forests, and can be applied to existing systems. We evaluate Chams with different topologies and show that it reduces the impact of churn, while imposing low computational and message overheads.