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Cisco ME 3400 EthernetAccess Switch SoftwareConfiguration Guide
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Chapter30 Co nf iguring QoS
Configuring QoS
After you have created the hierarchical output policy map, you attach it to an egress port. See the
“Attaching a Traffic Policy to an Interface” section on page30-35.
Use the no form of the appropriate command to delete an existing hierarchical policy map, to delete a
port shaping configuration, or to remove the policy map from the hier arc hica l p oli cy map.
This example shows how to configure port shaping by configuring a hierarchical policy m ap that shapes
a port to 90 Mbps, allocated according to the out-policy policy map configured in the previous example.
Switch(config)# policy-map out-policy-parent
Switch(config-pmap)# class class-default
Switch(config-pmap-c)# shape average 90000000
Switch(config-pmap-c)# service-policy out-policy
Switch(config-pmap-c)# exit
Switch(config-pmap)# exit
Switch(config)# interface fastethernet0/1
Switch(config-if)# service-policy output out-policy-parent
Switch(config-if)# exit
Configuring Output Policy Maps with Class-Based Priority Queuing
You can use the priority policy-map class configuration command to ensure that a particular class of
traffic is given preferential treatment. With strict priority queuing, the priority queue is constantly
serviced; all packets in the queue are scheduled and sent until the queue is empty. Excessive use of the
priority queues can possibly delay packets in other queues and cre at e unnec e ssary c on gest ion.
You can configure strict priority queuing (priority without police), or you can configure an uncon ditional
priority policer (priority with police). Follow these guidelines when configuring priority queuing:
•You can associate the priority command with a single unique class for all attached output policies
on the switch.
•When you configure a traffic class as a priority queue, you ca n co nfigur e only police and
queue-limit as other queuing actions for the same class. You cannot configure bandwidth or shape
average with priority queues in the same class.

Configuring Priority Without Police

Follow these guidelines when configuring strict priority queuing (priority without police):
•You cannot configure priority queuing without policing for a traffic class when class-based shaping
(shape average) or CBWFQ (bandwidth) is configured for another class within the output
policy-map.
•When you configure priority queuing without policing for a traffic class, you can only configure the
other queues for sharing by using the bandwidth remaining percent policy-map class
configuration command to allocate excess bandwidth. This command does not guarantee the
allocated bandwidth, but does ensure the rate of distribution.
Step11 show policy-map [policy-map-name [class
class-map-name]] Verify your entries.
Step12 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose