H3C Technologies H3C S10500 Series Switches - Manual (Page 165)

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Configuring a voice VLAN
Configuration prerequisites
Before you configure a voice VLAN, complete the following tasks:
• Create a VLAN.
• Configure QoS priority settings for voice VLAN traffic on an interface before you enable voice
VLAN on the interface.
If the configuration order is reversed, your priority configuration will fail. For more information, see
“ Configuring QoS priority settings for voice traffic on an interface .”
• Configure the voice VLAN assignment mode.
For more information, see “ Configuring a port to operate in automatic voice VLAN assignment mode ”
and “ Configuring a port to operate in manual voice VLAN assignment mode .”
Configuring QoS priority settings for voice traffic on an
interface
In voice VLAN applications, you can improve the quality of voice traffic by configuring the appropriate
QoS priority settings, including the Class of Service (CoS) and Differentiated Services Code Point (DSCP)
values, for voice traffic. Voice traffic carries its own QoS priority settings. You can configure the device
either to modify or not to modify the QoS priority settings carried by incoming voice traffic.
Follow these steps to configure QoS priority settings for voice traffic:
To do... Use the command... Remarks
Enter system view system-view —
Enter Layer 2 Ethernet interface
view
interface interface-type
interface-number
—
Configure the interface to trust the
QoS priority settings in incoming
voice traffic, but not to modify the
CoS and DSCP values marked for
incoming traffic of the voice VLAN
voice vlan qos trust
Configure the interface to modify
the CoS and DSCP values marked
for incoming traffic of the voice
VLAN into specified values
voice vlan qos cos-value
dscp-value
Required
Use either command
By default, an interface modifies the CoS
value and the DSCP value marked for voice
VLAN traffic into 6 and 46 respectively.
The voice vlan qos command and the voice
vlan qos trust command can overwrite each
other, whichever is configured last.
NOTE:
Configure the QoS priority settings for voice traffic on an interface before you enable voice VLAN on the
interface. If the configuration order is reversed, your priority trust setting will fail.
Configuring a port to operate in automatic voice VLAN
assignment mode
Follow these steps to set a port to operate in automatic voice VLAN assignment mode: