Overlay routing to avoid BGP path inflation

Several studies have shown that the BGP protocol adopts a special routing policy such that the default BGP route is usually not the best choice in terms of path length or quality of service. In order to send the traffic through the shortest AS paths by overlay routing, we have to place overlay nodes at several critical points along such paths. Otherwise, these AS paths will never be available to end users. In this paper, we explore the method for deploying a BGP-aware overlay routing network. First, we formulate the task of overlay deployment as a novel optimization problem. Then we divide this optimization problem into two sub-problems and conquer them with different algorithms respectively. Finally we investigate the layout of the overlay derived from simulations and identify the major force that causes the AS-level path inflation. By simulation experiments, we conclude that we can derive a cost-efficient overlay with our methodology to provider a better routing service for a given set of pair-wise inter-domain connections.