Reference Guide

Quality of Service 475
The following is an example of the CLI command:
Queue
The switch supports four queues for the R1-2401 device and eight queues for
the R1-2210 device for each interface. Queue number four and eight is the
highest priority queue for the R1-2401 and R1-2210 devices, respectively.
Queue number one is the lowest priority queue.
Traffic Limitation Methods
There are two ways of determining how traffic in queues is handled, Strict
Priority and Weighted Round Robin (WRR):
• Strict Priority — Egress traffic from the highest-priority queue is
transmitted first. Traffic from the lower queues is processed only after the
highest queue has been transmitted, thus providing the highest level of
priority of traffic to the lowest-numbered queue.
•
Weighted Round Robin (WRR) — In WRR mode, the number of packets
sent from the queue is proportional to the weight of the queue (the higher
the weight, the more frames are sent). The type of WRR algorithm used in
the device is not the standard Deficit WRR (DWRR), but rather Shaped
Deficit WRR (SDWRR).
Combination of WRR and Strict Priority
The priority for handling traffic can be selected for each queue. When the
queuing mode is Weighted Round Robin for all queues, queues are serviced
according to their weights. If all queues are assigned strict priority, queues are
serviced according to that order.
The following is true if some queues are assigned strict priority and others are
assigned WRR:
• If one queue is assigned strict priority, all higher queues are also assigned
strict priority. Conversely, if a queue is assigned a WRR weight, all lower
queues must also have a WRR weight assigned to them.
console(config)# interface gi0/8
console(config-if)# qos cos 3