On the relevance of correlation dependencies in on/off characterization of broadband traffic

The paper presents joint measurements of IP and ATM traffic over an MPOA based campus network. The search for parsimonious realistic modeling of heterogeneous aggregated traffic has led to the generalization of on/off modeling schemes. Even a single on/off pattern with Pareto-geometric distributions of the sojourn times in each state determines a hyperbolic decay of the autocovariance function corresponding to long range dependence (LRIB). Hence, adequate on/off models can fit real traces corresponding to the multiplexing of several heterogeneous connections. In the paper, the on/off behavior of the traffic is evidenced at the ATM level. The relevant feature of the traces is that either the on and the off sojourn times could be well approximated by a light tailed distribution. The observed LRD behavior is due to the presence of correlation in the sequence of on (as well as off) periods lengths. In order to confirm this hypothesis, different synthetic traces were considered, verifying the LRD behavior by means of wavelet analysis. Implications of such state correlations on queueing behavior are then compared by means of discrete event simulations