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Configuring voice VLANs
Overview
A voice VLAN is used for transmitting voice traffic. When ports that connect to voice devices are
assigned to a voice VLAN, the system can configure QoS parameters for voice packets to ensure
higher transmission priority and sound voice quality.
Common voice devices include IP phones and integrated access devices (IADs). This chapter uses
IP phone as an example.
For an IP phone to access a device, the device must perform the following operations:
•
Identify the IP phone in the network and obtain the MAC address of the IP phone.
•
Advertise the voice VLAN information to the IP phone.
After receiving the voice VLAN information, the IP phone can perform automatic configuration, so the
voice packets sent from the IP phone can be transmitted within the voice VLAN.
Methods of identifying IP phones
Devices can use the OUI addresses or LLDP to identify IP phones.
Identifying IP phones through OUI addresses
A device determines whether a received packet is a voice packet based on its source MAC address.
A packet whose source MAC address complies with any of the Organizationally Unique Identifier
(OUI) addresses of the voice devices is regarded as voice traffic.
You can use system default OUI addresses (see
) or configure OUI addresses for the device.
You can manually remove or add the system default OUI addresses.
The switch supports 128 OUI addresses, including system default OUI addresses.
Table 10 Default OUI addresses
Number OUI
address
Vendor
1 0001-E300-0000
Siemens
phone
2 0003-6B00-0000
Cisco
phone
3 0004-0D00-0000
Avaya
phone
4 00D0-1E00-0000
Pingtel
phone
5 0060-B900-0000
Philips/NEC
phone
6 00E0-7500-0000
Polycom
phone
7 00E0-BB00-0000
3Com
phone
Typically, an OUI address refers to the first 24 bits of a MAC address (in binary notation) and is a
globally unique identifier that IEEE assigns to a vendor. However, OUI addresses in this chapter are
addresses that the system uses to determine whether a received packet is a voice packet. They are
the logical AND results of the
mac-address
and
oui-mask
arguments
in the
voice-vlan
mac-address
command.
