ISP Friend or Foe? Making P2P Live Streaming ISP-Aware

Current peer-to-peer systems are network-agnostic, often generating large volumes of unnecessary inter-ISP traffic. Although recent work has shown the benefits of ISP-awareness on bulk transfer applications, no studies have focused on optimizing P2P live streaming systems. These are harder to design, as data must be diffused to all receivers within short delays. In this paper we propose a novel scheme for ISP-friendly mesh-based live streaming. Each peer maintains two distinct sets of overlay neighbors, used respectively for local and global stream propagation. A dynamic unchoke mechanism minimizes inter-ISP traffic in normal operation, enabling it promptly when local diffusion is impaired, e.g., when fast local sources become suddenly unavailable. Our scheme is independent of the chunk scheduling algorithm, and thus can be applied to a wide range of existing systems. We have integrated our ISP-friendly scheme to our P2P live streaming prototype, and evaluated its performance through emulation and Planetlab experiments. Our results show that our scheme adapts quickly to churn and dynamic network conditions, and achieves up to a ten-fold reduction in transit traffic.