Worst case performance analysis of MPLS with a GPS-based packet scheduler

In this paper we propose an MPLS switch with a GPS-based scheduler to provide guaranteed QoS in the Internet. The considered scenarios include cases with sufficient labels or with limited number of labels under competing streams. Due to tractability issues in direct analysis, we use a worst case equivalent system model to obtain the theoretical upper bounds of delays and backlogs of the original system model. Simulation results are used to verify the analytical results. We can obtain the worst case delay bounds and the maximum backlogs. Furthermore, the trade-off among the number of labels, the worst delay bounds, and the maximum backlogs can be observed. With our model, one can determine the number of required labels according to the allowable delay and the available buffer size.