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Catalyst 2975 Switch Software Configuration Guide
OL-19720-02
Chapter 14 Configuring Voice VLAN
Understanding Voice VLAN
shows one way to connect a Cisco 7960 IP Phone.
Figure 14-1
Cisco 7960 IP Phone Connected to a Switch
Cisco IP Phone Voice Traffic
You can configure an access port with an attached Cisco IP Phone to use one VLAN for voice traffic
and another VLAN for data traffic from a device attached to the phone. You can configure access ports
on the switch to send Cisco Discovery Protocol (CDP) packets that instruct an attached phone to send
voice traffic to the switch in any of these ways:
•
In the voice VLAN tagged with a Layer 2 CoS priority value
•
In the access VLAN tagged with a Layer 2 CoS priority value
•
In the access VLAN, untagged (no Layer 2 CoS priority value)
Note
In all configurations, the voice traffic carries a Layer 3 IP precedence value (the default is 5 for voice
traffic and 3 for voice control traffic).
3-port
switch
P1
P3
P2
Access
port
Cisco IP Phone 7960
PC
101351
Phone
ASIC