Minimal backlogging method for estimation of available bandwidth

This paper is concerned with estimating the available bandwidth of a network path. We first develop a theory to estimate the available bandwidth of a queueing system. In order to estimate the available bandwidth, we propose a probing method called a minimal backlogging method, and a statistic based on the service rate of minimally backlogging probing traffic. We show that the available bandwidth of a queueing system can be estimated by the statistic if probing packets are sent to the queueing system by the minimal backlogging method. For a network path consisting of multiple hops, we extend the approach for a single server by introducing a simplified path model. Since the proposed mechanism can estimate the available bandwidth quickly and track it adaptively, a reasonable range of available bandwidth for a short time interval can be obtained using the mean and variance of the estimated available bandwidth. The performance of the proposed available bandwidth estimation mechanism is evaluated by simulation in a multiple hop network topology.