374 Configuring Switch Information
Configuring Voice VLAN
Voice VLAN allows network administrators enhance VoIP service by configuring ports to carry IP voice
traffic from IP phones on a specific VLAN. VoIP traffic has a preconfigured OUI prefix in the source
MAC address. Network Administrators can configure VLANs on which voice IP traffic is forwarded.
Non-VoIP traffic is dropped from the Voice VLAN in auto Voice VLAN secure mode. Voice VLAN also
provides QoS to VoIP, ensuring that the quality of voice does not deteriorate if the IP traffic is received
unevenly. The system supports one Voice VLAN.
There are two operational modes for IP Phones:
• IP phones are configured with VLAN-mode as enabled, ensuring that tagged packets are used for all
communications.
• If the IP phone’s VLAN-mode is disabled, the phone uses untagged packets. The phone uses untagged
packets while retrieving the initial IP address through DHCP. The phone eventually use the Voice
VLAN and start sending tagged packets.
This section contains the following topics:
• Defining Voice VLAN Properties Page
• Defining Voice VLAN Port Settings
• Defining OUIs
This section contians the following topics:
• "Defining Voice VLAN Global Parameters" on page374
• "Defining Voice VLAN Port Settings" on page377
• "Defining OUIs" on page 379

Defining Voice VLAN Global Parameters

The Voice VLAN Global Parameters page contains parameters that apply to all Voice VLANs on the
device.
To open the Voice VLAN Global Parameters page, click Switch→ Voice VLAN → Global Parameters
inthe tree view.