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Cisco Unified IP Phone Administration Guide for Cisco Unified CallManager 5.1 (SIP), Cisco Unified IP Phones
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Chapter2 Preparing to Install the Cisco Unified IP Phone on Your Network
Providing Power to the Phone
Power Guidelines
Table 2 -1 provides guidelines that apply to external power and to inline power
power for phones the CiscoUnified IP Phones 7970G/7971G-GE.
Phone Power Consumption and Display Brightness
The power consumed by a phone depends on its power configuration. See
Table 2 -1 for a power configuration overview. See Table 2 -2 for the maximum
power consumed by a phone for each configuration option and the correlating
phone screen brightness level.
Note Power consumption values shown in the table include power losses in the cable
that connects the phone to the switch.
Table2-1 Guidelines for Powering the Cisco Unified IP Phones 7970G/7971G-GE
Power Type Guidelines
External power—
Provided through the
CP-PWR-CUBE-3
external power supply
The Cisco Unified IP Phones 7970G/7971G-GE 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 inline power patch panel WS-PWR-PANEL is not compatible
with the Cisco UnifiedIP Phones 7970G/7971G-GE.
•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.