Performance of in-call buffer/window allocation schemes for short intermittent file transfers over broadband packet networks

The author discusses two in-call buffer/window negotiation schemes for short intermittent file transfers, focusing on the specific needs of such traffic streams. A closed network of queues models is developed to show the behavior of the proposed schemes. These models, while simple, capture essential details of the control schemes. Under fairly general assumptions, the resulting network of queues is of product form and can be analyzed using the mean value analysis. The author uses such an analysis to compare the proposed schemes and to determine appropriate sizes of trunk buffers to achieve the desired balance between bandwidth utilization and file transfer delay. The effects of other parameters on the performance of these schemes as well as on the buffer sizing rules are discussed. In-call parameter negotiation may be carried out by the end system with the network elements or by the access controller with the internal network elements. The author discusses implications of this location as well as the needed protocol features. The service discrimination capabilities desired at the trunk controller in switching modes are discussed