ALTLAS: Accurate Topology Level-of-Detail Abstraction System

The ability to extract topology information from the network is important for many applications and enables more informed resource selection or application-level traffic routing. Given the size and complexity of networks, the challenge for topology exposure is to provide an aggregated view on a network that is sufficiently accurate and complies to topology hiding policies of network service providers. This paper presents a topology abstraction system that can expose large-scale service provider network maps with an adjustable level-of-detail. Routing topology data is often too detailed for an application. Our system uses mesh simplification algorithms in order to reduce the graph complexity and to obtain a more compact network representation compliant to abstraction policies. We extend the principle of edge contraction and we present an optimal abstraction algorithm to compensate the local error resulting from aggregating a weighted graph. Our numerical results reveal that the size of maps can be reduced by one order of magnitude or more while the result still enables reasonable traffic optimization inside applications. A proof-of-concept implementation gathers network management system data and exposes abstract maps through the Application-Layer Traffic Optimization (ALTO) protocol.