Obtaining Provably Legitimate Internet Topologies

What topologies should be used to evaluate protocols for interdomain routing? Using the most current Internet topology is not practical since its size is prohibitive for detailed, packet-level interdomain simulations. Besides being of moderate size, the topology should be policy-aware, that is, it needs to represent business relationships between adjacent nodes (that represent autonomous systems). In this paper, we address this issue by providing a framework to generate small, realistic, and policy-aware topologies. We propose HBR, a novel sampling method, which exploits the inherent hierarchy of the policy-aware Internet topology. We formally prove that our approach generates connected and legitimate topologies, which are compatible with the policy-based routing conventions and rules. Using simulations, we show that HBR generates topologies that: 1) maintain the graph properties of the real topology; 2) provide reasonably realistic interdomain simulation results while reducing the computational complexity by several orders of magnitude as compared to the initial topology. Our approach provides a permanent solution to the problem of interdomain routing evaluations: Given a more accurate and complete topology, HBR can generate better small topologies in the future.