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Automatically identifying IP phones through LLDP
When you use OUI addresses to identify IP phones, the number of OUI addresses that can be
configured is limited. Additionally, when there are plenty of IP phones in the network, you must
configure many OUI addresses. If IP phones support LLDP, configure LLDP on the device for
automatic IP phone discovery. For more information, see "
Enabling LLDP for automatic IP phone
Advertising the voice VLAN information to IP
phones
shows the workflow of advertising the voice VLAN information to IP phones.
Figure 48 Workflow of advertising the voice VLAN information to IP phones
After receiving the voice VLAN information, the IP phone automatically completes the voice VLAN
configuration.
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If the voice VLAN configuration is based on the received LLDP-MED TLVs or CDP packets, the
IP phone will send out packets tagged with the advertised voice VLAN ID. The voice packets
will be forwarded in the voice VLAN.
For more information about configuring LLDP or CDP, see "
." For more information about LLDP and CDP compatibility, see
"
."
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If the voice VLAN configuration is based on the authorization VLAN information, the IP phone
will send out packets tagged with the advertised authorization VLAN ID. The voice packets will
be forwarded in the authorization VLAN.
For more information about advertising the authorization VLAN information to IP phones, see
"
Dynamically advertising an authorization VLAN through LLDP or CDP
about authorization VLANs, see
Security Configuration Guide
.
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If the voice VLAN configuration is based on the voice VLAN information of the accessing port,
the voice traffic from the IP phone will be forwarded in the voice VLAN of the accessing port.
Whether the voice packets are tagged depends on the voice VLAN configuration of the
accessing port. For more information about configuring a voice VLAN on a port, see
"