Cisco Systems WSC4500X16SFP Manual De Usuario
27-19
Software Configuration Guide—Release 12.2(25)SG
OL-7659-03
Chapter 27 Configuring Quality of Service
Configuring Auto-QoS
•
To take advantage of the auto-QoS defaults, do not configure any standard-QoS commands before
entering the auto-QoS commands. If necessary, you can fine-tune the QoS configuration, but we
recommend that you do so only after the auto-QoS configuration is completed.
entering the auto-QoS commands. If necessary, you can fine-tune the QoS configuration, but we
recommend that you do so only after the auto-QoS configuration is completed.
•
You can enable auto-QoS on static, dynamic-access, voice VLAN access, and trunk ports.
•
By default, the CDP is enabled on all interfaces. For auto-QoS to function properly, do not disable
the CDP.
the CDP.
•
To enable auto qos voip trust on Layer 3 interfaces, change the port to Layer 3, then apply auto-QoS
to make it trust DSCP.
to make it trust DSCP.
Enabling Auto-QoS for VoIP
To enable auto-QoS for VoIP within a QoS domain, perform this task:
To disable auto-QoS on an interface, use the no auto qos voip interface configuration command. When
you enter this command, the switch changes the auto-QoS settings to the standard-QoS default settings
for that interface. It will not change any global configuration performed by auto-QoS. Global
configuration remains the same.
you enter this command, the switch changes the auto-QoS settings to the standard-QoS default settings
for that interface. It will not change any global configuration performed by auto-QoS. Global
configuration remains the same.
This example shows how to enable auto-QoS and to trust the CoS labels in incoming packets when the
device connected to Fast Ethernet interface 1/1 is detected as a Cisco IP phone:
device connected to Fast Ethernet interface 1/1 is detected as a Cisco IP phone:
Switch(config)# interface fastethernet1/1
Switch(config-if)# auto qos voip cisco-phone
Command
Purpose
Step 1
Switch# debug auto qos
(Optional) Enables debugging for auto-QoS. When debugging is
enabled, the switch displays the QoS commands that are
automatically generated and applied when auto-QoS is enabled or
disabled.
enabled, the switch displays the QoS commands that are
automatically generated and applied when auto-QoS is enabled or
disabled.
Step 2
Switch# configure terminal
Enters global configuration mode.
Step 3
Switch(config)# interface
interface-id
Enters interface configuration mode, and specify the interface that is
connected to a Cisco IP phone or the uplink interface that is
connected to another switch or router in the interior of the network.
connected to a Cisco IP phone or the uplink interface that is
connected to another switch or router in the interior of the network.
Step 4
Switch(config-if)# auto qos voip
{cisco-phone | trust}
Enables auto-QoS.
The keywords have these meanings:
•
cisco-phone—If the interface is connected to a Cisco IP phone,
the cos labels of incoming packets are trusted only when the
telephone is detected.
the cos labels of incoming packets are trusted only when the
telephone is detected.
•
trust—The uplink interface is connected to a trusted switch or
router, and the VoIP traffic classification in the ingress packet is
trusted.
router, and the VoIP traffic classification in the ingress packet is
trusted.
Step 5
Switch(config)# end
Returns to privileged EXEC mode.
Step 6
Switch# show auto qos interface
interface-id
Verifies your entries.
This command displays the auto-QoS configuration that was initially
applied; it does not display any user changes to the configuration that
might be in effect.
applied; it does not display any user changes to the configuration that
might be in effect.