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Cisco ME 3400 EthernetAccess Switch SoftwareConfiguration Guide
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Chapter30 Co nf iguring QoS
Configuring QoS
•A WTD qualifier in the queue-limit command must be the same as at least one match qualifier in
the associated class map.
This example shows how to configure bandwidth and queue limit so that out-class1 , out-class2, and
out-class3 get a minimum of 50, 20, and 10 percent of th e t raffic bandwi dth, a nd the r ema ini ng tr affic
(class-default) gets the remaining 20 percent. The corresponding queue-size is set to 48, 32, an d 16
(256-byte) packets, respectively:
Switch(config)# policy-map out-policy
Switch(config-pmap)# class outclass1
Switch(config-pmap-c)# bandwidth percent 50
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)# exit
Switch(config)# interface gigabitethernet 0/1
Switch(config-if)# service-policy output out-policy
Switch(config-if)# exit
Configuring QoS
Before configuring QoS, you must have a thorough understanding of these factors:
•The types of applications used and the traffic patterns on your network.
•Traffic characteristics and needs of your network. Is the traffic bursty? Do you need to reserve
bandwidth for voice and video streams?
•Bandwidth requirements and speed of the network.
•Location of congestion points in the network.
These sections describe how to classify, police, and mark incoming traffic, and sche dule and qu eu e
outgoing traffic. Depending on your network configuration, you must perform on e or mo re o f th ese
tasks.
•Default QoS Configuration, page 30-27
•QoS Configuration Guidelines, page 30-27
•Using ACLs to Classify Traffic, page 30-27
•Using Class Maps to Define a Traffic Class, page 30-31
•Configuring Table Maps, page 30-33
•Attaching a Traffic Policy to an Interface, page 30-35
•Configuring Input Policy Maps, page 30-35
•Configuring Output Policy Maps, page 30-43