PeerWise is an Internet routing overlay that reduces end-to-end latencies by allowing peers to forward through a relay instead of connecting directly to their destinations. Fundamental to PeerWise is the notion of peering agreements between two peers, wherein they agree to forward for one another. In this paper, we consider the problem of motivating users to establish and maintain peerings in a completely decentralized, scalable manner. We show that routing overlays present unique challenges

more »

... goals. For instance, since participants can always "fall back" on standard Internet routing, we must encourage users to stay in the system and maintain long-lived peering agreements. To address these challenges, we propose two mechanisms: First, we use Service Level Agreements (SLAs) to expressively negotiate peers' demands and the recourses they will take when SLAs are violated. Second, we propose a mechanism to address SLA violations that differs from the standard notion of punishment via service degradation. Our simulation results demonstrate that our mechanism causes peers to avoid SLA violators in favor of long-lived peerings. Lastly, we discuss potential, emergent behaviors in a selfish routing overlay.