Voice VLAN assignment modes
A port can be assigned to a voice VLAN in one of the following modes:
•
In automatic mode, the system matches the source MAC address carried in the untagged packets
sent when an IP phone is powered on against the device’s OUI addresses. If the system finds a
match, it automatically assigns the receiving port to the voice VLAN, issues ACL rules, and
configures the packet precedence. You can configure a voice VLAN aging time on the device. The
system will remove a port from the voice VLAN if no packet is received from the port during the
aging time. The system automatically assigns ports to, or removes ports from, a voice VLAN.
Automatic mode is suitable for scenarios where PCs and IP phones connected in series access the
network through the device and ports on the device transmit both voice traffic and data traffic at the
same time, as shown in
. When the voice VLAN works normally, when the system reboots,
the system reassigns ports in automatic voice VLAN assignment mode to the voice VLAN after the
reboot, ensuring that existing voice connections can work normally. In this case, voice traffic
streams do not trigger port assignment to the voice VLAN.
Figure 34
PCs and IP phones connected in series access the network
•
In manual mode, you must manually assign an IP phone accessing port to a voice VLAN. Then, the
system matches the source MAC addresses carried in the packets against the device’s OUI
addresses. If the system finds a match, it issues ACL rules and configures the packet precedence. In
this mode, you must manually assign ports to, or remove ports from, a voice VLAN. Manual mode
is suitable for scenarios where only IP phones access the network through the device and ports on
the device transmit only voice traffic, as shown in
. In this mode, ports assigned to a voice
VLAN transmit voice traffic exclusively, which prevents the impact of data traffic on the transmission
of voice traffic.
Figure 35
Only IP phones access the network
IP Phone
Switch
Voice gateway
IP Phone
Both modes forward tagged packets according to their tags.
list the configurations required for ports of different link types to support tagged
or untagged voice traffic sent from IP phones when different voice VLAN assignment modes are
configured.
•
IP phones send tagged voice traffic
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