H3C Technologies H3C S3100 Series Switches - Manual (Page 124)

1-7
Voice VLAN
Mode
Packet Type Processing Method
Packet carrying any other VLAN
tag
The packet is forwarded or dropped based on whether
the receiving port is assigned to the carried VLAN. The
processing method is irrelevant to the voice VLAN
mode (security or normal).
Untagged packet
Packet carrying the voice VLAN
tag
The source MAC address of the packet is not checked.
All such packets can be transmitted in the voice VLAN.
Normal
Packet carrying any other VLAN
tag
The packet is forwarded or dropped based on whether
the port is assigned to the carried VLAN. The
processing method is irrelevant to the voice VLAN
mode (security or normal).
Voice VLAN Configuration
Configuration Prerequisites
z Create the corresponding VLAN before configuring a voice VLAN.
z VLAN 1 (the default VLAN) cannot be configured as a voice VLAN.
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 interface view
interface interface-type
interface-number
—
Configure the interface to trust the
QoS priority settings in incoming
voice traffic, that is, 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.
Configure the QoS priority settings for voice traffic on an interface before enabling voice VLAN on the
interface. If the configuration order is reversed, your priority trust setting will fail.