161
Step Command
Remarks
2.
Enter Layer 2 Ethernet
interface view.
interface
interface-type
interface-number
N/A
3.
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
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.
4.
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
Configuring a port to operate in automatic voice VLAN
assignment mode
Configuration restrictions and guidelines
•
A protocol-based VLAN on a hybrid port can process only untagged inbound packets, whereas the
voice VLAN in automatic mode on a hybrid port can process only tagged voice traffic. Do not
configure a VLAN as both a protocol-based VLAN and a voice VLAN. For more information, see
•
Do not configure automatic voice VLAN assignment together with MSTP, because the former is
mainly configured on the access side. With MSTP enabled, if a port is blocked in the MST instance
(MSTI) of the target voice VLAN, the port drops the received packets, instead of delivering them to
the CPU. As a result, the receiving port will not be dynamically assigned to the corresponding
VLAN.
•
Do not configure automatic voice VLAN assignment together with PVST, because the former is
mainly configured on the access side. With PVST enabled, if the target voice VLAN is not permitted
on a port, the port is placed in the blocked state and drops the received packets, instead of
delivering them to the CPU. As a result, the receiving port will not be dynamically assigned to the
corresponding VLAN.
Configuration procedure
To set a port to operate in automatic voice VLAN assignment mode:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Set the voice VLAN aging
time.
voice vlan aging
minutes
Optional.
By default, the aging time of a
voice VLAN is 1440 minutes.
The voice VLAN aging time
configuration is only applicable on
ports in automatic voice VLAN
assignment mode.