55-14
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
OL-8978-04
Chapter 55 Configuring a VoIP Network
Configuring VoIP on a Switch
Each port also has a status that is defined as one of the following:
•
on—Power is supplied by the port.
•
off—Power is not supplied by the port.
•
Power-deny—The supervisor engine does not have enough power to allocate to the port, or the
power that is configured for the port is less than the power that is required by the port; the power is
not being supplied by the port.
•
err-disable—The port is unable to provide the power to the connected device that is configured in
Static mode.
•
faulty—The port failed the diagnostics tests.
These sections provide the information on the IP phone power requirements and management:
•
Power Requirements, page 55-14
•
Available Power, page 55-15
•
Wall-Powered Phones, page 55-15
•
Powering Off the Phone, page 55-15
•
Phone Removal, page 55-15
•
High-Availability Support, page 55-16
Power Requirements
The IP phones may have different power requirements.
Table 55-4
lists the power requirements for the
different classes of IP phones. The supervisor engine initially calculates the power allocation for each
port based on the per-port configuration, classification (IEEE only), and default power. When the correct
amount of power is determined from the CDP messaging with the Cisco IP Phone, the supervisor engine
reduces or increases the allocated power for any ports that are set to Auto mode. The allocated power is
not adjusted for ports that are set to Static mode.
For example, the default allocated power is 7 W for a Cisco IP Phone requiring 6.3 W. The supervisor
engine allocates 7 W for the Cisco IP Phone and powers it up. Once the Cisco IP Phone is operational,
it sends a CDP message with the actual power requirement to the supervisor engine. The supervisor
engine then decreases the allocated power to the required amount if the port is set to Auto mode. If the
port is set to Static mode, the supervisor engine allocates the wattage that you specified. If the port is set
to off, the supervisor engine does not allot any power to the port.
Table 55-4
Power Requirements for IP Phones
Phone Class
Required Power (W)
Cisco 6.3
Cisco + IEEE
7
Cisco High Power
15.4
Class 0 IEEE
15.4
Class 1 IEEE
4
Class 2 IEEE
7.0
Class 3
15.4
Class 4 Refer to Class 0
Reserved
