Cisco SG220-26 - Configuring Qos Queues

Quality of Service
Workflow to Configure QoS Settings
Cisco 220 Series Smart Switches Administration Guide Release 1.1.0.x 252
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STEP 6 Click Apply. The interface’s default CoS value is changed, and the Running
Configuration is updated.
STEP 7 To restore the CoS value to factory defaults, check the interfaces and click
Restore Defaults.
Configuring QoS Queues
The switch supports eight queues for each interface. Queue number 8 is the
highest priority queue. Queue number 1 is the lowest priority queue.
There are two ways of determining how traffic in queues is handled, Strict Priority
(SP) and Weighted Round Robin (WRR).
• Strict Priority (SP)—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, which provide the highest level of
priority of traffic to the highest 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 queuing modes can be selected on the Queue
page . When the queuing mode
is by Strict Priority, the priority sets the order in which queues are serviced,
starting with queue_8 (the highest priority queue) and going to the next lower
queue when each queue is completed.
When the queuing mode is Weighted Round Robin, queues are serviced until their
quota has been used up and then another queue is serviced.
It is also possible to assign some of the lower queues to WRR, while keeping some
of the higher queues in Strict Priority. In this case traffic for the SP queues is
always sent before traffic from the WRR queues. After the SP queues have been
emptied, traffic from the WRR queues is forwarded. (The relative portion from
each WRR queue depends on its weight).