Overlay Routing Over an Uncooperative Underlay

Overlay network is a non-intrusive mechanism to enhance the existing network infrastructure by building a logical distributed system on top of a physical underlay. A major difficulty in operating overlay networks is the lack of cooperation from the underlay, which is usually under a different network administration. In particular, the lack of knowledge about the underlay topology and link capacities makes the design of efficient overlay routing extremely difficult. In contrast to existing solutions for overlay routing based on simplistic assumptions such as known underlay topology or disjoint routing paths through the underlay, we aim at systematically optimizing overlay routing without causing congestion, by extracting necessary information about the underlay from measurements taken at overlay nodes. To this end, we (i) identify the minimum information for congestion-free overlay routing, and (ii) develop polynomial-complexity algorithms to infer this information with guaranteed accuracy. Our evaluations in NS3 based on real network topologies demonstrate notable performance advantage of the proposed solution over existing solutions.