Voice Vlan Commands - Dell N1100-ON Reference Manual

Voice VLAN Commands

Dell EMC Networking N1100-ON/N1500/N2000/N2100-
ON/N3000/N3100-ON/N4000 Series Switches
The Voice VLAN feature enables switch ports to carry voice traffic with an
administrator-defined priority so as to enable prioritization of voice traffic
over data traffic. Using Voice VLAN helps to ensure that the sound quality of
an IP phone is protected from deterioration when the data traffic utilization
on the port is high.
Voice VLAN is the preferred solution for applying QoS to voice traffic in an
enterprise environment. Voice VLAN scales with the number of ports and
does not make significant demands on the switch CPU for classification of
voice traffic. However, Voice VLAN does require the administrator to perform
the additional configuration step of defining the QoS policy to be applied to
voice traffic.
The switch can be configured to support voice VLAN on a port connecting to
the VoIP phone. When a VLAN is associated with the voice VLAN port, then
the VLAN ID information is passed onto the VoIP phone using LLDP-MED.
Voice data coming from the VoIP phone is tagged by the phone with the
transmitted VLAN ID; regular data arriving on the switch is given the default
PVID of the port.
When an IEEE 802.1p priority is associated with the voice VLAN port, then
the priority information is passed to the VoIP phone using LLDP-MED. It is
expected that the voice data coming from the VoIP phone is tagged with
VLAN 0 or the voice VLAN and with the transmitted priority. Configure the
voice vlan data priority on the port to enable the switch to transmit the IEEE
802.1p or DSCP values to the phone in the LLDP-MED Network Policy TLV.
Regular data arriving on the switch is given the default priority of the port
(default 0) and the voice traffic is received with the priority assigned by the
phone, allowing the switch to provide distinguished service to the voice
traffic.
The switch can be configured to override the voice traffic CoS by entering an
internal ACL associated with the MAC address of the IP phone. Alternatively,
a diffserv policy can be configured for the voice VLAN which assigns voice
traffic to a queue and also remarks the CoS or DSCP values in the voice
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Layer 2 Switching Commands