(m; P;s) { an Eecient Background Traac Model for Wide-area Network Simulation P; S) { an Eecient Background Traac Model for Wide-area Network Simulation 2

This paper presents a background traac model, (M; P;S), designed for use in wide-area packet-switched network simulators. The approach is to model the aggregate traac generated by a large campus network and then partition the aggregate traac into substreams, one for each campus-level destination in the backbone network. We use packet traces collected at the network exchange point of a large campus network and the global Internet to motivate our model design and demonstrate that our approach generates realistic results. Key features of the proposed model include: (1) eeciency { the generation of only a single long-range dependent stream is required for each campus network, (2) simplicity { the statistical properties (i.e., arrival density and correlation structure) of the sample path are controlled by a few parameters, and (3) accuracy { the self-similarity and arrival distribution for both the aggregate traac and its component substreams accurately reproduce those of the empirical traac trace. The results presented in this paper can be used to develop WAN background load models and traac generators, contribute to understanding the fractal behavior of Internet backbone network utilization, and provide a benchmark to evaluate the accuracy of existing traac models.