Configuring Voice Vlan; Default Voice Vlan Configuration - Cisco 2950 - Catalyst Switch Configuration Manual

Configuring Voice VLAN

Figure 19-1
Figure 19-1 Cisco 7960 IP Phone Connected to a Switch
When the IP Phone connects to the switch, the access port (PC-to-telephone jack) of the IP phone can
connect to a PC. Packets to and from the PC and to or from the IP phone share the same physical link to
the switch and the same switch port. For deployment examples that use voice VLANs, refer to
the"Network Configuration Examples" section on page
Configuring Voice VLAN
This section describes how to configure voice VLAN on access ports. It contains this configuration
information:
•
•
•

Default Voice VLAN Configuration

The voice VLAN feature is disabled by default.
When the voice VLAN feature is enabled, all untagged traffic is sent according to the default CoS
priority of the port.
The default CoS value is 0 for incoming traffic.
The CoS value is not trusted for 802.1p or 802.1Q tagged traffic.
The IP Phone overrides the priority of all incoming traffic (tagged and untagged) and sets the CoS value
to 0.
Note In software releases earlier than Cisco IOS Release 12.1(13)EA1, the CoS value is trusted for all 802.1p
or 802.1Q tagged traffic, and the IP Phone does not override the priority of the incoming traffic.
Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
19-2
shows one way to connect a Cisco 7960 IP Phone.
Cisco IP Phone 7960
P1
Default Voice VLAN Configuration, page 19-2
Voice VLAN Configuration Guidelines, page 19-3
Configuring a Port to Connect to a Cisco 7960 IP Phone, page 19-3
Phone
ASIC
P2
P3
3-port
switch
Access
port
1-10.
Chapter 19 Configuring Voice VLAN
PC
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