Cisco Small Business 200 Administration Manual page 322

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STEP 1
STEP 2
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• 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). For example, if there are a maximum of
four queues possible and all four queues are WRR and the default weights
are used, queue1 receives 1/15 of the bandwidth (assuming all queues are
saturated and there is congestion), queue 2 receives 2/15, queue 3 receives
4/15 and queue 4 receives 8 /15 of the bandwidth. The type of WRR
algorithm used in the device is not the standard Deficit WRR (DWRR), but
rather Shaped Deficit WRR (SDWRR).
The queuing modes can be selected in the Queue page. When the queuing mode
is by strict priority, the priority sets the order in which queues are serviced,
starting with Queue 4 or 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 strict priority
queues is always sent before traffic from the WRR queues. Only after the strict
priority queues have been emptied is traffic from the WRR queues forwarded.
(The relative portion from each WRR queue depends on its weight).
To select the priority method and enter WRR data.
Click Quality of Service > General > Queue.
Enter the parameters.
• Queue—Displays the queue number.
• Scheduling Method: Select one of the following options:
- Strict Priority
queues is based strictly on the queue priority.
WRR
- —Traffic scheduling for the selected queue is based on WRR. The
period time is divided between the WRR queues that are not empty,
meaning they have descriptors to egress. This happens only if strict
priority queues are empty.
- WRR Weight
queue.
% of WRR Bandwidth
-
the queue. These values represent the percent of the WRR weight.
—Traffic scheduling for the selected queue and all higher
—If WRR is selected, enter the WRR weight assigned to the
—Displays the amount of bandwidth assigned to
Cisco Small Business 200 Series Smart Switch Administration Guide
Quality of Service
Configuring QoS - General