Voice Vlan - Dell PowerConnect 8024 User Configuration Manual

misconfiguration while exiting the metro core. For example, if the edge
device on the other side of the metro core is not stripping the second tag, the
packet would never be classified as a 802.1Q tag, so the packet would be
dropped rather than forwarded in the incorrect VLAN.
Figure 22-2. Double VLAN Tagging Network Example
802.1Q Domain
Customer A
ID = 50
Data .1Q Tag
Link Vlan ID Payload
Header 22
.1Q Tagged Frame
Data .1Q Tag
Link Vlan ID Payload
Header 33

Voice VLAN

The Voice VLAN feature enables switch ports to carry voice traffic with
defined priority. When multiple devices, such as a PC and an IP phone, are
connected to the same port, you can configure the port to use one VLAN for
voice traffic and another VLAN for data traffic.
Voice over IP (VoIP) traffic is inherently time-sensitive: for a network to
provide acceptable service, the transmission rate is vital. The priority level
enables the separation of voice and data traffic coming onto the port.
A primary benefit of using Voice VLAN is to ensure that the sound quality of
an IP phone is safeguarded from deteriorating when the data traffic on the
port is high. The switch uses the source MAC address of the traffic traveling
through the port to identify the IP phone data flow.
Edge Device
Metro Core
DVLAN Tagged Frame
DVlan
Data
Tag
Link
Vlan ID
Header
DVlan
Data
Tag
Link
Vlan ID
Header
Edge Device
.1Q Tag
Vlan ID Payload
22
50
.1Q Tag
Vlan ID Payload
33
60
Configuring VLANs
802.1Q Domain
Customer B
ID = 60
Data .1Q Tag
Link Vlan ID Payload
Header 22
.1Q Tagged Frame
Data .1Q Tag
Link Vlan ID Payload
Header 33
545