Cisco SD208T-NA Administration Manual page 166

VLAN Management
Voice VLAN
Cisco Small Business 200 Series Smart Switch Administration Guide
From a VLAN perspective, the above models operate in both VLAN-aware and
VLAN-unaware environments. In the VLAN-aware environment, the voice VLAN is
one of the many VLANs configured in an installation. The VLAN-unaware scenario
is equivalent to a VLAN-aware environment with only one VLAN.
The switch always operates as a VLAN-aware switch.
The switch supports a single voice VLAN. By default, the voice VLAN is VLAN 1.
The voice VLAN is defaulted to VLAN 1. A different voice VLAN can be manually
configured. It can also be dynamically learned when Auto Voice VLAN is enabled.
Ports can be manually added to the voice VLAN by using basic VLAN
configuration described in the
manually applying voice-related Smartport macro to the ports. Alternatively, they
can be added dynamically if the switch is in Telephony OUI mode, or has Auto
Smartports enabled.
Dynamic Voice VLAN Modes
The switch supports two dynamic voice VLAN modes: Telephony OUI
(Organization Unique Identifier) mode and Auto Voice VLAN mode. The two
modes affect how voice VLAN and/or voice VLAN port memberships are
configured. The two modes are mutually exclusive to each other.
• Telephony OUI
In Telephony OUI mode, the voice VLAN must be a manually-configured
VLAN, and cannot be the default VLAN.
When the switch is in Telephony OUI mode and a port is manually
configured as a candidate to join the voice VLAN, the switch dynamically
adds the port to the voice VLAN if it receives a packet with a source MAC
address matching to one of the configured telephony OUIs. An OUI is the
first three bytes of an Ethernet MAC address. For more information about
Telephony OUI, see
• Auto Voice VLAN
In Auto Voice VLAN mode, the voice VLAN can be either the default voice
VLAN, manually configured, or learned from external devices such as
UC3xx/5xx and from switches that advertise voice VLAN in CDP or VSDP.
VSDP is a Cisco defined protocol for voice service discovery.
Configuring VLAN Interface Setting
Configuring Telephony
section, or by
OUI.
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