Configuring Cisco IP Phone Support
Cisco IP Phone Data Traffic
Untagged traffic from the device attached to the Cisco IP Phone passes through the Cisco IP Phone
unchanged, regardless of the trust state of the access port on the Cisco IP Phone.
To process tagged data traffic (traffic in 802.1Q or 802.1p frame types) from the device attached to the
access port on the Cisco IP Phone (see
switch to send CDPv2 packets that instruct an attached Cisco IP Phone to configure the access port on
the Cisco IP Phone to either of these two modes:
Cisco IP Phone Power Configurations
These sections describe Cisco IP Phone power configurations:
Locally Powered Cisco IP Phones
There are two varieties of local power:
When a locally powered Cisco IP Phone is present on a switching module port, the switching module
cannot detect its presence. The supervisor engine discovers the Cisco IP Phone through CDPv2
messaging with the Cisco IP Phone.
If a locally powered Cisco IP Phone loses local power and the mode is set to auto, the switching module
discovers the Cisco IP Phone and informs the supervisor engine, which then supplies inline power to the
Cisco IP Phone.
Inline-Powered Cisco IP Phones
Inline power is from switching modules that support an inline power daughtercard. Inline power is sent
over the twisted-pair Ethernet cable to the Cisco IP Phone.
For information about switching modules that support inline power, refer to the Release Notes for Cisco
IOS Release 12.1E on the Catalyst 6000 and Cisco 7600 Supervisor Engine and MSFC publication at
Trusted mode—All traffic received through the access port on the Cisco IP Phone passes through
the Cisco IP Phone unchanged.
Untrusted mode—All traffic in 802.1Q or 802.1p frames received through the access port on the
Cisco IP Phone is marked with a configured Layer 2 CoS value. The default Layer 2 CoS value is 0.
Untrusted mode is the default.
Locally Powered Cisco IP Phones, page 11-3
Inline-Powered Cisco IP Phones, page 11-3
From a power supply connected to the Cisco IP Phone
From a power supply through a patch panel over the twisted-pair Ethernet cable to the
Cisco IP Phone
Catalyst 6500 Series Switch Cisco IOS Software Configuration Guide—Release 12.1 E
11-1), you can configure Layer 2 access ports on the
Understanding Cisco IP Phone Support