Cisco Catalyst 2950 Command Reference Manual page 49

Chapter 2 Catalyst 2950 and 2955 Cisco IOS Commands
When you enable the auto-QoS feature on the first interface, these automatic actions occur:
When you enter the auto qos voip cisco-phone interface configuration command on a port at the
•
edge of the network that is connected to a Cisco IP Phone, the switch enables the trusted boundary
feature. The switch uses the Cisco Discovery Protocol (CDP) to detect the presence or absence of a
Cisco IP Phone. When a Cisco IP Phone is detected, the ingress classification on the interface is set
to trust the QoS label received in the packet. When a Cisco IP Phone is absent, the ingress
classification is set to not trust the QoS label in the packet. The egress queues on the interface are
also reconfigured (see
When you enter the auto qos voip cisco-softphone interface configuration command on a port at
•
the edge of the network that is connected to a device running the Cisco SoftPhone, the switch uses
policing to decide whether a packet is in or out of profile and to specify the action on the packet. If
the packet does not have a DSCP value of 24, 26, or 46 or is out of profile, the switch changes the
DSCP value to 0. The egress queues on the interface are also reconfigured (see
When you enter the auto qos voip trust interface configuration command on a port connected to the
•
interior of the network, the ingress classification on the interface is set to trust the QoS label received
in the packet, and the egress queues on the interface are reconfigured (see
You can enable auto-QoS on static, dynamic-access, voice VLAN access, and trunk ports.
When a device running Cisco SoftPhone is connected to a switch or routed port, the switch supports only
Note
one Cisco SoftPhone application per port.
After auto-QoS is enabled, do not modify a policy map or aggregate policer that includes AutoQoS in its
name. If you need to modify the policy map or aggregate policer, make a copy of it, and change the
copied policy map or policer. To use the new policy map instead of the generated one, remove the
generated policy, and apply the new policy map.
To display the QoS configuration that is automatically generated when auto-QoS is enabled, enable
debugging before you enable auto-QoS. Use the debug auto qos privileged EXEC command to enable
auto-QoS debugging.
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.
To disable auto-QoS on the switch and return to the default port trust state (untrusted), follow these steps:
Use the no auto qos voip interface configuration command on all interfaces on which auto-QoS is
1.
enabled. To disable auto-QoS on multiple interfaces at the same time, you can use the
range
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:
•
•
•
OL-10102-01
Table 2-2).
global configuration command.
no wrr-queue bandwidth
no wrr-queue cos-map
no mls qos map cos-dscp
Catalyst 2950 and Catalyst 2955 Switch Command Reference
auto qos voip
Table 2-2).
Table 2-2).
interface
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