Specifications

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Cisco ME 2400 Ethernet Access Switch Command Reference
OL-9643-03
Chapter 2 Cisco ME 2400 Ethernet Access Switch Cisco IOS Commands
queue-limit
Usage Guidelines You use the queue-limit policy-map class command to control output traffic. Queue-limit settings are
not supported in input policy maps.
Beginning with Cisco IOS Release 12.2(35)SE, the switch supports one output policy map for each
interface. However the limit of three unique queue-limit configurations across all output policy maps
remains in effect You can use the same queue-limit configuration across multiple policy maps.
Within an output policy map only four queues (classes) are allowed, including the class default. Each
queue has three defined thresholds (queue limits). Only three queue-limit configurations are allowed on
the switch, but multiple policy maps can share the same queue-limits. For two policy maps to share a
queue-limit configuration, all threshold values must be the same for all classes in both policy maps.
If you try to attach an output policy map that contains a fourth queue-limit configuration to an interface,
you see an error message and the attachment is not allowed.
The queue-limit command is supported only after you first configure a scheduling action, such as
bandwidth, shape-average, or priority, except when you configure queue-limit in the class-default of
an output policy map.
You cannot configure more than two unique threshold values for WTD qualifiers (cos, dscp,
precedence, or qos-group) in the queue-limit command. However, you can map any number of
qualifiers to those thresholds. You can configure a third unique threshold value to set the maximum
queue, using the queue-limit command with no qualifiers.
When you use the queue-limit command to configure thresholds within a class map, the WTD thresholds
must be less than or equal to the maximum threshold of the queue. This means that the queue size
configured without a qualifier must be larger than any of the queue sizes configured with a qualifier.
Examples This example shows how to configure WTD so that out-class1, out-class2, out-class3, and class-default
get a minimum of 40, 20, 10 and 10 percent of the traffic bandwidth respectively. The corresponding
queue-sizes are set to 48, 32, 16 and 272 (256-byte) packets:
Switch(config)# policy-map out-policy
Switch(config-pmap)# class outclass1
Switch(config-pmap-c)# bandwidth percent 40
Switch(config-pmap-c)# queue-limit 48
Switch(config-pmap-c)# exit
Switch(config-pmap)# class outclass2
Switch(config-pmap-c)# bandwidth percent 20
Switch(config-pmap-c)# queue-limit 32
Switch(config-pmap-c)# exit
Switch(config-pmap)# class outclass3
Switch(config-pmap-c)# bandwidth percent 10
Switch(config-pmap-c)# queue-limit 16
Switch(config-pmap-c)# exit
Switch(config-pmap)# class class-default
Switch(config-pmap-c)# bandwidth percent 10
Switch(config-pmap-c)# queue-limit 272
Switch(config-pmap-c)# exit
Switch(config-pmap)# exit
Switch(config)# interface gigabitethernet 0/1
Switch(config-if)# service-policy output out-policy
Switch(config-if)# exit