Voice VLAN assignment modes
A port connected to a voice device, an IP phone for example, can be assigned to a voice VLAN in one
of the following modes:
Automatic mode—The system matches the source MAC addresses in the protocol packets
(untagged packets) sent by the IP phone upon its power-on against the OUI list. If a match is found,
the system automatically assigns the receiving port to a voice VLAN, issues ACL rules and
configures the packet precedence. You can configure an aging timer for the voice VLAN. The
system will remove the port from the voice VLAN when the aging timer expires if no voice packet is
received on the port during the aging timer. 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 simultaneously
transmit both voice traffic and data traffic, as shown in
correctly, if the system reboots, the system reassigns ports in automatic voice VLAN assignment
mode to the voice VLAN after the reboot, making sure existing voice connections can work correctly.
In this case, voice traffic streams do not trigger port assignment to the voice VLAN.
Figure 153 PCs and IP phones connected in series access the network
Manual mode—You must assign the port to a voice VLAN manually. Then, the system matches the
source MAC addresses in the packets against the OUI addresses. If a match is found, the system
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
exclusively, which prevents the impact of data traffic on the transmission of voice traffic.
Figure 154 Only IP phones access the network
Both modes forward tagged packets according to their tags.
or untagged voice traffic sent from IP phones when different voice VLAN assignment modes are
154. In this mode, ports assigned to a voice VLAN transmit voice traffic
list the configurations required for ports of different link types to support tagged
153. When the voice VLAN works