27-49
Cisco ME 3800X and 3600X Switch Software Configuration Guide
OL-23400-01
Chapter 27 Configuring QoS
Configuring QoS
Switch(config-pmap)#
exit
Switch(config)#
interface gigabitethernet0/1
Switch(config-if)#
service-policy output out-policy-parent
Switch(config-if)#
exit
Configuring 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. Strict priority queuing provides low-latency service to the class.
•
When priority is configured in an output policy map without the police command, you can only
configure the other queues for sharing by using the bandwidth remaining percent policy-map
command to allocate excess bandwidth.
•
You cannot configure priority and bandwidth for the same class.
•
You can apply priority at the class level and to the VLAN level.
•
You can associate the priority command with a single class at the class level and a single class at the
VLAN level.
Beginning in privileged EXEC mode, follow these steps to configure a strict priority queue:
After you have created an output policy map, you attach it to an egress port or EFP. See the
“Attaching
a Service Policy to an Interface or EFP” section on page 27-56
.
Use the no form of the appropriate command to delete an existing policy map or class map or to cancel
strict priority queuing for the priority class or the bandwidth setting for the other classes.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
class-map class-map-name
Create classes for three egress queues. Enter match conditions
classification for each class.
Step 3
policy-map policy-map-name
Create a policy map by entering the policy map name, and enter
policy-map configuration mode.
Step 4
class class-map-name
Enter the name of the priority class (created by using the class-map
global configuration command), and enter policy-map class
configuration mode for the priority class.
Step 5
priority
Set the strict scheduling priority for this class.
Note
Only one unique class map in an attached policy map can be
associated with a priority command. You cannot configure
priority along with any other queuing action (bandwidth or
shape average).
Step 6
exit
Exit policy-map class configuration mode for the priority class.
Step 7
class class-map-name
Enter the name of a nonpriority class, and enter policy-map class
configuration mode for that class.
Step 8
bandwidth remaining percent value
Set output bandwidth limits for the policy-map class as a percentage of
the remaining bandwidth. The range is 0 to 100 percent.
Step 9
end
Return to privileged EXEC mode.
Step 10
show policy-map
Verify your entries.
Step 11
copy running-config startup-config
(Optional) Save your entries in the configuration file.
