Specifications

2-4
Cisco Unified IP Phone Administration Guide for Cisco Unified Communications Manager 8.5
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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.