3Com Switch 7750 Configuration Guide Guide

11
VOICE VLAN CONFIGURATION
Voice VLAN Overview Voice VLANs are VLANs configured specially for voice data stream. By adding the
ports with voice devices attached to voice VLANs, you can perform QoS (quality of
service)-related configuration for voice data, ensuring the transmission priority of
voice data stream and voice quality.
Switch 7750 Family Ethernet switches determine whether a received packet is a
voice packet by checking its source MAC address. If the source MAC addresses of
packets comply with the organizationally unique identifier (OUI) addresses
configured by the system, the packets are determined as voice packets and
transmitted in voice VLAN.
You can configure an OUI address for voice packets or specify to use the default
OUI address.
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An OUI address is a globally unique identifier assigned to a vendor by IEEE. You
can determine which vendor a device belongs to according to the OUI address
which forms the first 24 bits of a MAC address.
The following table shows the five default OUI addresses of a switch.
A voice VLAN can operate in two modes: automatic mode and manual mode. You
can configure the operation mode for a voice VLAN according to data stream
passing through the ports of the voice VLAN.
■ In automatic mode, the Switch 7750 Family automatically adds a port
connecting a IP voice device to the voice VLAN through learning the source
MAC address in the untagged packet sent by the IP voice device when it is
powered on. When the aging time of a port expires, voice ports on which the
OUI addresses are not updated (no voice stream passes) will be automatically
removed from the voice VLAN; voice ports cannot be added into or removed
from the voice VLAN through manual configurations.
■ In manual mode: you need to execute related configuration commands to add
a voice port to the voice VLAN or remove a voice port from the voice VLAN.
Table 49 Default OUI addresses preset by the switch
Number OUI Address Vendor
1 0003-6b00-0000 Cisco phone
2 000f-e200-0000 3Com Aolynk phone
3 00d0-1e00-0000 Pingtel phone
4 00e0-7500-0000 Polycom phone
5 00e0-bb00-0000 3com phone