Cisco Systems OL-23092-01 Providing Power to the Phone, Power Guidelines, Power Type Guidelines

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 2-1provides 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		The Cisco Unified IP Phone 7975G, 7971G-GE, 7970G, 7965G, and 7945G use the
through the CP-PWR-CUBE-3		CP-PWR-CUBE-3 power supply.
external power supply
External power—		The Cisco Unified IP Phone Power Injector may be used with any Cisco Unified IP Phone.
Provided through the Cisco		Functioning as a midspan device, the injector delivers inline power to the attached phone.
Unified IP Phone Power Injector		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		• The Cisco Unified IP Unified IP Phones 7975G, 7971G-GE, 7970G, 7965G, and
switch through the Ethernet		7945G support IEEE 802.3af Class 3 power on signal pairs and spare pairs.
cable attached to the phone		• 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.

Cisco Unified IP Phone Administration Guide for Cisco Unified Communications Manager 8.5

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