Configuring Output Policy Maps With Class-Based Priority Queuing - Cisco ME 3400G-2CS - Ethernet Access Switch Software Configuration Manual

Configuring QoS
Command
Step 11 show policy-map [policy-map-name [class
class-map-name]]
Step 12
copy running-config startup-config
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 page
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 hierarchical policy map.
This example shows how to configure port shaping by configuring a hierarchical policy map 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 create unnecessary congestion.
You can configure strict priority queuing (priority without police), or you can configure an unconditional
priority policer (priority with police). Follow these guidelines when configuring priority queuing:
•
•
Configuring Priority Without Police
Follow these guidelines when configuring strict priority queuing (priority without police):
•
•
Cisco ME 3400 Ethernet Access Switch Software Configuration Guide
30-48
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 can configure 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.
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.
Purpose
Verify your entries.
(Optional) Save your entries in the configuration file.
30-35.
Chapter 30 Configuring QoS
78-17058-01