Inferring Catchment in Internet Routing

Abstract

BGP is the de-facto Internet routing protocol for interconnecting Autonomous Systems (AS). Each AS selects its preferred routes based on its routing policies, which are typically not disclosed. Due to the distributed route selection and information hiding, answering questions such as "what is the expected catchment of the anycast sites of a content provider at the AS-level, if new sites are deployed?", or "how will load-balancing behave if an ISP changes its routing policy for a prefix?", is a hard challenge. In this work, we propose a framework and methodology to infer the routing behavior in existing or hypothetical routing configurations, and provide new capabilities and insights for informative route inference (e.g., isolating the effect of randomness that is present in prior simulation-based approaches). The proposed framework can be useful in a number of applications: measurements/monitoring, traffic engineering, network planning, Internet routing models, etc.