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Table 13 Packet processing on a voice VLAN-enabled port in normal and security mode
Voice VLAN
mode
Packet type
Packet processing
Normal
Untagged packets or
packets with the voice
VLAN tags
The port does not examine the source MAC addresses of
incoming packets. Both voice traffic and non-voice traffic can
be transmitted in the voice VLAN.
Packets with other VLAN
tags
Forwarded or dropped depending on whether the port allows
packets from these VLANs to pass through.
Security
Untagged packets or
packets with the voice
VLAN tags
•
If the source MAC address of a packet matches an OUI
address on the device, the packet is forwarded in the
voice VLAN.
•
If the source MAC address of a packet does not match
an OUI address on the device, the packet is dropped.
Packets with other VLAN
tags
Forwarded or dropped depending on whether the port allows
packets from these VLANs to pass through.
Configuration prerequisites
Before you configure a voice VLAN, complete the following tasks:
•
Create a VLAN.
•
Determine the QoS priority settings for voice VLAN traffic.
•
Determine the voice VLAN assignment mode.
Configuring the QoS priority settings for voice traffic
The QoS priority settings carried in voice traffic include the CoS and DSCP values. You can
configure the device to modify the QoS priority settings for voice traffic.
Before you configure the QoS priority settings for voice traffic on a port, make sure the voice VLAN
feature is disabled on it.
To configure the QoS priority settings for voice traffic:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter Layer 2 Ethernet
interface view.
interface
interface-type
interface-number
N/A
3.
Configure QoS priority
settings for incoming voice
VLAN packets.
•
Configure the port to trust and
retain the QoS priority settings:
a.
Use the 802.1p priority in
incoming packets for priority
mapping:
qos trust dot1p
b.
Configure the port to trust
and retain the QoS priority
settings:
voice-vlan qos
trust
•
Configure the port to modify the
CoS and DSCP values:
voice-vlan qos cos-value
dscp-value
By default, a port modifies the
CoS and DSCP values for
voice VLAN packets to 6 and
46, respectively.
If you execute the
voice-vlan
qos
and
voice-vlan qos trust
commands multiple times, the
most recent configuration
takes effect.
For more information about the
qos trust dot1p
command,
see
ACL and QoS Command
Reference
.