VLAN Management
Voice VLAN
Cisco 350XG & 550XG Series 10G Stackable Managed Switches
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NOTE
The device can synchronize with VSDP capable switches in the same
management VLAN.and in the directly-connected IP subnets configured at
the device.
Auto Smartport works with CDP/LLDP to maintain the port memberships of the
voice VLAN when voice end-points are detected from the ports:
•
When CDP and LLDP are enabled, the device sends out CDP and LLDP
packets periodically to advertise the voice VLAN to the voice endpoints to
use.
•
When a device attaching to a port advertises itself as a voice endpoint
through CDP and/or LLDP, the Auto Smartport automatically adds the port
to the voice VLAN by applying the corresponding Smartport macro to the
port (if there is no other devices from the port advertising a conflicting or
superior capability). If a device advertises itself as a phone, the default
Smartport macro is phone. If a device advertises itself as a phone and host
or phone and bridge, the default Smartport macro is phone+desktop.
Voice VLAN QoS
Voice VLAN can propagate the CoS/802.1p and DSCP settings by using LLDP-
MED Network policies. The LLDP-MED is set by default to response with the Voice
QoS setting if an appliance sends LLDP-MED packets. MED-supported devices
must send their voice traffic with the same CoS/802.1p and DSCP values, as
received with the LLDP-MED response.
You can disable the automatic update between Voice VLAN and LLDP-MED and
use his own network policies.
Working with the OUI mode, the device can additionally configure the mapping
and remarking (CoS/802.1p) of the voice traffic based on the OUI.
By default, all interfaces are CoS/802.1p trusted. The device applies the quality
of service based on the CoS/802.1p value found in the voice stream. In Auto Voice
VLAN, you can override the value of the voice streams using advanced QoS. For
Telephony OUI voice streams, you can override the quality of service and
optionally remark the 802.1p of the voice streams by specifying the desired CoS/
802.1p values and using the remarking option under Telephony OUI.
Voice VLAN Constraints
The following constraints exist:
•
Only one Voice VLAN is supported.
•
A VLAN that is defined as a Voice VLAN cannot be removed
