User`s guide

DES-3226S Layer 2 Switch CLI Reference
143
To use implement round-robin (weighted) priority, the switch’s four priority
queues can be configured to reduce the buffer in a round-robin fashion -
beginning with the highest priority queue, and proceeding to the lowest
priority queue before returning to the highest priority queue.
The weighted-priority based scheduling alleviates the main disadvantage of
strict priority-based scheduling − in that lower priority queues get starved of
bandwidth − by providing a minimum bandwidth to all queues for
transmission. This is accomplished by configuring the maximum number of
packets allowed to be transmitted from a given priority queue and the
maximum amount of time a given priority queue will have to wait before being
allowed to transmit its accumulated packets. This establishes a Class of
Service (CoS) for each of the switch’s four hardware priority queues.
The possible range for maximum packets is: 0 to 255 packets.
The possible range for maximum latency is: 0 to 255 (in increments of 16
microseconds each).