How to Model an Internetwork.

Graphs are commonly used to model the structure of internetworks, for the study of problems ranging from routing to resource reservation. A variety of graph models are found in the literature, including regular topologies such as rings or stars, "well-known" topologies such as the original ARPAnet, and randomly generated topologies. Less common is any discussion of how closely these models correlate with real network topologies. We consider the problem of efficiently generating graph models that accurately reflect the topological properties of real internetworks. We compare properties of graphs generated using various methods with those of real internets. We also propose efficient methods for generating topologies with particular properties, including a Transit-Stub model that correlates well with Internet structure. Improved models for internetwork structure have the potential to impact the significance of simulation studies of in-ternetworking solutions, providing basis for the validity of the conclusions.