312
Configuring Voice VLAN
How to Configure Voice VLAN
When you enable port security on an interface that is also configured with a voice VLAN, you must set the
maximum allowed secure addresses on the port to two plus the maximum number of secure addresses allowed
on the access VLAN. When the port is connected to a Cisco IP phone, the phone requires up to two MAC
addresses. The phone address is learned on the voice VLAN and might also be learned on the access VLAN.
Connecting a PC to the phone requires additional MAC addresses.
Port Connection to a Cisco 7960 IP Phone
Because a Cisco 7960 IP Phone also supports a connection to a PC or other device, a port connecting the switch to a
Cisco IP phone can carry mixed traffic. You can configure a port to decide how the Cisco IP phone carries voice traffic
and data traffic.
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 instruct the 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 phone to not change (trust) or to override (not trust) the priority of frames arriving on the
phone port from connected devices.
How to Configure Voice VLAN
Configuring the Priority of Incoming Data Frames
Monitoring and Maintaining Voice VLAN
Command Purpose
1. configure terminal Enters global configuration mode.
2. interface interface-id Specifies the interface connected to the Cisco IP phone, and enters interface
configuration mode.
3. switchport priority extend
{cos value | trust}
Sets the priority of data traffic received from the Cisco IP phone access port:
cos value—Configures the 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 to 7, with 7 as the highest priority. The default priority
is cos 0.
trust—Configures the phone access port to trust the priority received
from the PC or the attached device.
4. end Returns to privileged EXEC mode.
Command Purpose
show interfaces interface-id switchport Verifies your entries.
copy running-config startup-config Saves your entries in the configuration file.
To Next Page
Loading...
Need help?
General