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Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
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Chapter 29 Configuring QoS
Configuring Auto-QoS
Enabling Auto-QoS for VoIP
Beginning in privileged EXEC mode, follow these steps to enable auto-QoS for VoIP within a QoS
domain:
To disable auto-QoS on the switch and return to the default port trust state set (untrusted), follow these
steps:
1. Use the no auto qos voip interface configuration command on all interfaces on which auto-QoS is
enabled. To disable auto-QoS on multiple interfaces at the same time, you can use the interface
range global configuration command.
2. After disabling auto-QoS on all interfaces on which auto-QoS was enabled, return the egress queues
and CoS-to-DSCP map to the default settings by using these global configuration commands:
• no wrr-queue bandwidth
• no wrr-queue cos-map
• no mls qos map cos-dscp
To display the QoS commands that are automatically generated when auto-QoS is enabled or disabled,
enter the debug auto qos privileged EXEC command before enabling auto-QoS. For more information,
see the “Using the debug auto qos Command” section on page 31-20.
This example shows how to enable auto-QoS and to trust the QoS labels in incoming packets when the
device connected to the interface is detected as a Cisco IP Phone:
Switch(config)# interface
Switch(config-if)# auto qos voip cisco-phone
This example shows how to enable auto-QoS and to trust the QoS labels in incoming packets when the
switch or router connected to the interface is a trusted device:
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 interface interface-id Specify the interface that is connected to a Cisco IP Phone, and enter
interface configuration mode. You also can specify the uplink interface
that is connected to another trusted witch or router in the interior of the
network.
Step 3 auto qos voip {cisco-phone | trust} Enable auto-QoS.
The keywords have these meanings:
• cisco-phone—If the interface is connected to a Cisco IP Phone,
the QoS labels of incoming packets are trusted only when the IP
phone is detected.
• trust—The uplink interface is connected to a trusted switch or
router, and the VoIP classification in the ingress packet is trusted.
Step 4 end Return to privileged EXEC mode.
Step 5 show auto qos interface interface-id Verify your entries.
This command displays the auto-QoS command on the interface on
which auto-QoS was enabled. You can use the show running-config
privileged EXEC command to display the auto-QoS configuration and
the user modifications.