Users Guide

Network Administration: Quality of Service 229
FILE LOCATION: C:\Users\gina\Desktop\Checkout_new\Dell Astute\User
Guide\Dell_Astute_Network_Admin_QoS.fm
DELL CONFIDENTIAL – PRELIMINARY 8/9/16 - FOR PROOF ONLY
• 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.
• In the above case, traffic for the strict priority queues is always sent before
traffic from the WRR queues. Traffic from the WRR queues is forwarded
only after the strict priority queues have been emptied. The relative
portion from each WRR queue depends on its weight.
To select the priority method and enter WRR weights:
1
Click Network Administration > Quality of Service > Global Settings >
Queue Scheduling .
The queues are displayed.
2 Click Enter and enter the following parameters for each queue:
–
Scheduling Method — Select one of the following options for each
queue:
•
Strict Priority — Check to indicate that traffic scheduling for the
selected queue, and all higher queues, is based strictly on the
queue priority.
•
WRR — Check to indicate that traffic scheduling for the selected
queue is based on WRR. The time period 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.