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Cisco Unified IP Phone Administration Guide for Cisco Unified Communications Manager 8.5
OL-23092-01
Chapter 2 Preparing to Install the Cisco Unified IP Phone on Your Network
Providing Power to the Phone
Providing Power to the Phone
Cisco Unified IP Phone 7975G, 7971G-GE, 7970G, 7965G, and 7945G can be powered with external
power or with Power over Ethernet (PoE). External power is provided through a separate power supply.
PoE is provided by a switch through the Ethernet cable attached to a phone.
Note
When you install a phone that is powered with external power, connect the power supply to the phone
and to a power outlet before you connect the Ethernet cable to the phone. When you remove a phone that
is powered with external power, disconnect the Ethernet cable from the phone before you disconnect the
power supply.
The following sections provide more information about powering a phone:
•
Power Guidelines, page 2-4
•
Phone Power Consumption and Display Brightness, page 2-5
•
Power Outage, page 2-6
•
Obtaining Additional Information about Power, page 2-6
Power Guidelines
Table 2-1
provides guidelines that apply to external power and to PoE power for Cisco Unified IP Phone
7975G, 7971G-GE, 7970G, 7965G, and 7945G.
Table 2-1
Guidelines for Powering the Cisco Unified IP Phone 7975G, 7971G-GE, 7970G, 7965G, and 7945G
Power Type
Guidelines
External power— Provided
through the CP-PWR-CUBE-3
external power supply
The Cisco Unified IP Phone 7975G, 7971G-GE, 7970G, 7965G, and 7945G use the
CP-PWR-CUBE-3 power supply.
External power—
Provided through the Cisco
Unified IP Phone Power Injector
The Cisco Unified IP Phone Power Injector may be used with any Cisco Unified IP Phone.
Functioning as a midspan device, the injector delivers inline power to the attached phone.
The Cisco Unified IP Phone Power Injector is connected between a switch port and the
IP Phone, and supports a maximum cable length of 100m between the unpowered switch
and the IP Phone.
PoE power—Provided by a
switch through the Ethernet
cable attached to the phone
•
The Cisco Unified IP Unified IP Phones 7975G, 7971G-GE, 7970G, 7965G, and
7945G support IEEE 802.3af Class 3 power on signal pairs and spare pairs.
•
The Cisco Unified IP Unified IP Phones 7975G, 7971G-GE, 7970G, 7965G, and
7945G do not support Cisco inline PoE.
•
To ensure uninterruptible operation of the phone, make sure that the switch has a
backup power supply.
•
Make sure that the CatOS or IOS version running on your switch supports your
intended phone deployment. Refer to the documentation for your switch for operating
system version information.
