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Catalyst 2960 Switch SoftwareConfiguration Guide
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Chapter14 Configuring Voice VLAN
Displaying Voice VLAN
To return the port to its default setting, use the no switchport voice vlan interface configuration
command.

Configuring the Priority of Incoming Data Frames

You can connect a PC or other data device to a Cisco IP Phone port. To process tagged data traffic (in
IEEE 802.1Q or IEEE 802.1p frames), you can configure the switch to send CDP packets to i nstruct the
IP Phone how to send data packets from the device attached to the access port on the Cisco IP Phone.
The PC can generate packets with an assigned CoS value. You can configure the Cisco IP Phone to not
change (trust) or to override (not trust) the priority of frame s arriving on the IP Phone port from
connected devices.
Beginning in privileged EXEC mode, follow these steps to set the priority of data traffic received from
the nonvoice port on the Cisco IP Phone:
This example shows how to configure a port connected to an IP Pho ne to not change the priority of
frames received from the PC or the attached device:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# switchport priority extend trust
Switch(config-if)# end
To return the port to its default setting, use the no switchport priority extend interface configuration
command.
Displaying Voice VLAN
To display voice VLAN configuration for an interface, use the show interfaces interface-id switchport
privileged EXEC command.
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 interface interface-id Specify the interface connected to the IP Phone, and enter interface
configuration mode.
Step3 switchport priority extend
{cos value | trust}
Set the priority of data traffic received from the IP Phone access port:
•cos value—Configure the IP Phone to override the priority received from
the PC or the attached device with the specified CoS value. The value is
a number from 0 to7, with 7 as the highest priority. The default priority
is cos 0.
•trust—Configure the IP Phone access port to trust the priority received
from the PC or the attached device.
Step4 end Return to privileged EXEC mode.
Step5 show interfaces interface-id
switchport
Verify your entries.
Step6 copy running-config
startup-config
(Optional) Save your entries in the configuration file.