Bessie: portable generation of network topologies for simulation

The widespread use of computer networking has resulted in considerable attention being paid to a variety of network-related problems, the generation of efficient multicast trees being one. While many algorithms for generation of multicast trees have been proposed their relative effectiveness is difficult to assess. Some algorithms have never been implemented. Many have been simulated, but often using ad-hoc networking modeling and simulation tools, without consistent parameters, making direct comparisons difficult. In this paper we discuss a network topology generation tool named Bessie, written entirely in Java. Bessie generates descriptions of random point-to-point and hierarchical networks, based on user-specified statistical parameters. We introduce a modification to Waxman's (1988) parameters, commonly used in grid-based network topology generators, which eliminates undesirable increases in node degree as the number of nodes in a network increases. The modification improves on proposed fixed scale factors.