Incentive-compatible interdomain routing

Abstract

The routing of traffic between Internet domains, or Autonomous Systems (ASes), a task known as interdomain routing, is currently handled by the Border Gateway Protocol (BGP) [17]. Using BGP, autonomous systems can apply semantically rich routing policies to choose interdomain routes in a distributed fashion. This expressiveness in routing-policy choice supports domains' autonomy in network operations and in business decisions, but it comes at a price: The interaction of locally defined routing policies can lead to unexpected global anomalies, including route oscillations or overall protocol divergence (see, e.g., [20]). Networking researchers have addressed this problem by devising constraints on policies that guarantee BGP convergence without unduly limiting expressiveness and autonomy (see, e.g., [7, 8]).In addition to taking this engineering or protocol-design approach, researchers have approached interdomain routing from an economic or mechanism-design point of view. It is known that lowest-cost-path (LCP) routing can be implemented in a truthful, BGP-compatible manner [3] but that several other natural classes of routing policies cannot [2, 5]. In this paper, we present a natural class of interdomain-routing policies that is more realistic than LCP routing and admits incentive-compatible, BGP-compatible implementation. We also present several positive steps toward a general theory of incentive-compatible interdomain routing.