On the performance of bursty and modulated sources subject to leaky bucket rate-based access control schemes

摘要

Provides an analysis of a rate-based access control scheme in high speed environments based on a buffered leaky bucket algorithm. The analysis is carried out in discrete time which is representative of an ATM environment. For the cell arrivals to the leaky bucket the authors consider a general discrete Markovian arrival process which models bursty and modulated sources. The key of the analysis is the introduction of the deficit junction that allows the reduction of the original problem to a more standard discrete time queueing system with the same arrival process. As an important special case, the detailed analysis of the binary Markov source throttled by such rate-based access control schemes is presented. Along with explicit recursions for computation of state probabilities and simple characterisation of the asymptotic behavior of the queue build up, some guidelines for the parameter selection of these schemes are provided. The results indicate that for sources with relatively large active periods, for an acceptable grade-of-service at the input queue, the token generation rate should be chosen to be close to the peak rate of the source, and increasing the bucket size of the leaky bucket does not improve substantially the performance at the input queue.