Modeling Internet Topology with GT-ITM

Problem
Several years ago, we developed a software package for generating graphs that have a structure modeling the topology of the Internet. The package (GT-ITM) has been widely used by networking researchers to create topologies used in simulation studies of networking algorithms and protocols. The most useful topology generation method in the package is the Transit-Stub model. Recently we became aware of a bug in the implementation of this model, which may or may not affect the high-level characteristics of the topologies that are generated.

This project consists of (1) fixing the bug (which should be quite straightforward) and (2) running some experiments to generate topologies and assess characteristics to determine the impact of the bug. The experiments will generally involve repeating what has been reported in the literature by other authors who have assessed the transit-stub topologies.

Preparation for the project includes reading the paper Modeling Internet Topology, Calvert, Doar and Zegura, IEEE Communications Magazine, June 1997. You should also get a copy of the source code for the GT-ITM package, available here. Please contact me to discuss the bug and for guidance on the experiments that you should run.