Estimating network link characteristics using packet-pair dispersion: A discrete-time queueing theoretic analysis

We present a queueing theoretic analysis of packet-dispersion based probing. The links are modeled as independent discrete-time queues with i.i.d. arrivals. We first derive an algorithm to obtain the (joint) distribution of the separation between the probes at the destination(s) for a given distribution of the spacing at the input. The parameter estimates of the arrival processes are obtained as the minimizer of a cost function between the empirical and calculated distributions. We also carry out extensive simulations and numerical experiments on the model to study the performance of the estimation algorithm for some non stationary arrival process. We find that the estimations work fairly well for two queues in series and for multicast. We also identify issues related to packet-dispersion based parameter estimation when there are multiple queues.