Understanding Internet topology: principles, models, and validation

Abstract

The article of record as published may be found at: http://dx.doi.org/10.1109/NET.2005.861250Building on a recent effort that combines a first-principles approach to modeling router-level connectivity with a more pragmatic use of statistics and graph theory, we show in this paper that for the Internet, an improved understanding of its physical infrastructure is possible by viewing the physical connectivity as an annotated graph that delivers raw connectivity and bandwidth to the upper layers in the TCP/IP protocol stack, subject to practical constraints (e.g. router technology) and economic considerations (e.g., link costs). More importantly, by relying on data from Ablilene, a Tier -1 ISP, and the Rocketfuel project, we provide empirical evidence in support of the proposed approach and its consistency with networking reality. To illustrate this utility, we: 1) show that our approach provides insight into the origin of high variability in measured or inferred router-level maps,: 2) demonstrate that it easily accommodates the incorporation of additional objectives of network design (e.g., robustness to router failure); and 3) discuss how it complements ongoing community efforts to reverse-engneer the Internet