Performance evaluation of a window-based approach for ATM cell scheduling

The major potential of high speed ATM networks is the efficient and flexible support of different kinds of traffic and diverse services. This can, however, only be realized when an effective hardware switch with a good priority scheduler is available. Prioritized cells should be handled in an appropriate manner during cell discarding and scheduling. We propose a cell selection scheme for ATM switches with multiple priorities. The window-based scheduling mechanism chooses cells for dispatching from the higher priority queues before the lower priority queues up to a certain maximum level during a certain period of time. When a service priority queue consumes its maximum allowable cells, other services with less priority are allowed to send. Simulations of the switch with the new dispatching mechanism is run under a diversity of bursty traffic load. A comparison between this scheme and an alternative is also discussed.