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Configuring a voice VLAN
Overview
A voice VLAN is configured for voice traffic. After assigning the ports that connect to voice devices to a
voice VLAN, the system automatically configures quality of service (QoS) parameters for voice traffic, to
improve the transmission priority of voice traffic and ensure voice quality.
Common voice devices include IP phones and integrated access devices (IADs). Only IP phones are used
in the voice VLAN configuration examples in this document.
When an IP phone accesses a device, the device must have completed the following tasks:
•
Identifying the IP phone and obtaining the MAC address of the IP phone, so that the device can
perform security authentication for the IP phone and increase the priority for voice traffic.
•
Advertising the voice VLAN information to the IP phone, so that the IP phone can automatically
configure the voice VLAN according to the received information and the voice packets sent out of
the IP phone can be transmitted within the voice VLAN.
Methods of identifying IP phones
OUI addresses
A device determines whether a received packet is a voice packet by evaluating its source MAC address.
A packet whose source MAC address complies with the Organizationally Unique Identifier (OUI)
address of the voice device is regarded as voice traffic.
You can remove the default OUI address of a device manually and then add new ones manually. You can
configure the OUI addresses of a device in advance or use the default OUI addresses.
lists the
default OUI address for each vendor's devices. The switch supports 128 OUI addresses.
Table 15
The default OUI addresses of different vendors
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
In general, as the first 24 bits of a MAC address (in binary format), an OUI address is a globally unique
identifier that IEEE assigns to a vendor. In this document, however, OUI addresses are addresses that the
system uses to determine whether a received packet is a voice packet. They are the results of the AND
operation of the arguments
mac-address
and
oui-mask
in the
voice vlan mac-address
command.
