Simulating Internet Scale Topologies with Metarouting

Research on Internet routing algorithms can benefit greatly by easily repeatable large-scale simulations conducted on realistic network topologies. Unfortunately, it is a challenging task to develop clear and unambiguous definitions of a routing protocol and its associated policies. Simulations often only operate on small scale topologies. Even if simulators could handle very large scale topologies, it is unclear whether we have accurate topologies that also capture policies. This paper leverage existing work on metarouting[6] to provide a large scale simulator. The simulator takes as input a topology and routing protocol/policy described using RAML[6]. We use a RAML description of BGP to evaluate the accuracy of some of the most popular AS level topologies. Our results reveal both strengths and weaknesses in these topologies. In particular, the results suggest the addition of a siblings policy actually reduces accuracy and topologies could improve by instead incorporating rules for selective prefix announcement.