Chapter 14 Configuring Voice Vlan - Cisco Catalyst 3550 series Software Configuration Manual

Configuring Voice VLAN
Figure 14-1
Figure 14-1 Cisco 7960 IP Phone Connected to a Switch
Catalyst 2950, 2955,
or 3550 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.
Catalyst 3550 Multilayer Switch Software Configuration Guide
14-2
shows one way to connect a Cisco 7960 IP Phone.
Cisco IP Phone 7960
P1
Default Voice VLAN Configuration, page 14-2
Voice VLAN Configuration Guidelines, page 14-3
Configuring a Port to Connect to a Cisco 7960 IP Phone, page 14-3
Phone
ASIC
P2
P3
3-port
switch
Access
port
1-9.
Chapter 14 Configuring Voice VLAN
PC
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