IronPort Systems ES-1528 - Manual (Page 73)

Chapter 11 QoS
ES-1528 User’s Guide
73
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.