Rehoming edge links for better traffic engineering

Abstract

Traditional traffic engineering adapts the routing of traffic within the network to maximize performance. We propose a new approach that also adaptively changes where traffic enters and leaves the network---changing the "traffic matrix", and not just the intradomain routing configuration. Our approach does not affect traffic patterns and BGP routes seen in neighboring networks, unlike conventional inter-domain traffic engineering where changes in BGP policies shift traffic and routes from one edge link to another. Instead, we capitalize on recent innovations in edge-link migration that enable seamless rehoming of an edge link to a different internal router in an ISP backbone network---completely transparent to the router in the neighboring domain. We present an optimization framework for traffic engineering with migration and develop algorithms that determine which edge links should migrate, where they should go, and how often they should move. Our experiments with Internet2 traffic and topology data show that edge-link migration allows the network to carry 18.8% more traffic (at the same level of performance) over optimizing routing alone.