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Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
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Chapter 18      Configuring Voice VLAN
    Configuring Voice VLAN
• Configuring the IP Phone to Trust the CoS Priority of Incoming Data Frames, page 18-6
Configuring Ports to Carry Voice Traffic in IEEE 802.1Q Frames
Beginning in privileged EXEC mode, follow these steps to configure a port to carry voice traffic in IEEE 
802.1Q frames for a specific VLAN:
To remove voice VLAN, use the no switchport voice vlan interface configuration command or the 
switchport voice vlan none interface configuration command.
Configuring Ports to Carry Voice Traffic in IEEE 802.1p Priority-Tagged Frames
Beginning in privileged EXEC mode, follow these steps to configure a port to instruct the IP phone to 
give voice traffic a higher priority and to forward all traffic through the native VLAN.
To return the port to its default setting, use the no switchport voice vlan interface configuration 
command.
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
interface interface-id Specify the interface connected to the IP phone, and enter interface 
configuration mode.
Step 3
switchport voice vlan vlan-id Instruct the Cisco IP Phone to forward all voice traffic through the specified 
VLAN. By default, the Cisco IP Phone forwards the voice traffic with 
an IEEE 802.1Q priority of 5.
Valid VLAN IDs are from 1 to 4094.
Step 4
end Return to privileged EXEC mode.
Step 5
show interfaces interface-id 
switchport 
Verify your voice VLAN entries.
Step 6
copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
interface interface-id Specify the interface connected to the IP phone, and enter interface 
configuration mode.
Step 3
switchport voice vlan dot1p  Instruct the switch port to use IEEE 802.1p priority tagging for voice traffic 
and to use the default native VLAN (VLAN 0) to carry all traffic. By default, 
the Cisco IP phone forwards the voice traffic with an IEEE 802.1p priority 
of 5.
Step 4
end Return to privileged EXEC mode.
Step 5
show interfaces interface-id 
switchport 
Verify your voice VLAN entries.
Step 6
copy running-config startup-config (Optional) Save your entries in the configuration file.