IronPort Systems ES-1528 User Manual

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 Chapter 11 QoS
ES-1528 User’s Guide
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The following table describes the labels in this screen.  
11.3.1  Change Number of Queues  
Use the Change Number of Queues screen to edit the number of queues on the switch. Click 
Change in the QoS Setting screen to view the following screen.
Figure 37   Change Number of Queues 
Select the number of queues from the Number of Queues drop down list box and click Apply 
to save your settings to the switch. 
Table 17   QoS Setting 
LABEL
DESCRIPTION
Advanced
Click this link to configure QoS settings based on port number, IP address or configure 
DSCP or ToS priority to 802.1p priority mappings.
Number of 
queues
This field displays the number of queues configurable on the switch. Click Change to edit 
the number of queues on the switch.
Scheduling 
Method
Select Strict Priority or Weighted Round Robin.
Strict Priority scheduling singles out the highest priority queue and ensures all queued 
traffic in this queue is transmitted before servicing the lower priority queues. Strict 
Priority scheduling services the remaining queues using WRR. 
Note: Queue weights can only be changed when Weighted Round 
Robin is selected. 
Weighted Round Robin scheduling services queues on a rotating basis based on their 
queue weight (the number you configure in the queue Weight field). Queues with larger 
weights get more service than queues with smaller weights.
Priority
This value indicates packet priority and is retrieved from the priority tag field of incoming 
packets. The values range from 0 (lowest priority) to 7 (highest priority). Click the options 
below the priority values to send packets of a specific priority to a particular queue. You 
can also set this priority based on criteria you configure in the Advanced QoS screens. 
See the sections later in this chapter for more information.
Queue 0 ... 
Queue 3
This field indicates which Queue (0 to 3) you are configuring. Queue 0 has the lowest 
priority and Queue 3 the highest priority.
Weight
You can only configure the queue weights when Weighted Round Robin is selected. 
Bandwidth is divided across the different traffic queues according to their weights. 
Note: If you want to use Strict Priority but want to change the 
weights for the queues, configure them with Weighted Round 
Robin selected first and then change the scheduling method 
to Strict Priority. 
Apply
Click Apply to save your changes to the switch.