Power Outage - Cisco 9971 Administration Manual

Power Type
External power—Provided
through the Cisco Unified
IP Phone Power Injector.
PoE power—Provided by a
switch through the Ethernet
cable attached to the phone.
The documents in the following table provide more information on the following topics:
• Cisco switches that work with Cisco Unified IP Phones
• Cisco IOS releases that support bidirectional power negotiation
• Other requirements and restrictions about power
Document Topics
Cisco Unified IP Phone Power Injector
PoE Solutions
Cisco Catalyst Switches
Integrated Service Routers
Cisco IOS Software

Power Outage

Your access to emergency service through the phone requires that the phone receive power. If a power
interruption occurs, service or emergency calling service dialing does not function until power is restored. If
Cisco Unified IP Phone 8961, 9951, and 9971 Administration Guide for Cisco Unified Communications Manager 10.0
Guidelines
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 connects
between a switch port and the IP Phone, and supports a maximum cable length
of 100m between the unpowered switch and the IP phone.
Cisco Unified IP Phone 8961, 9951, and 9971 supports IEEE 802.3af Class 3
power on signal pairs and spare pairs.
Cisco Unified IP Phone 8961, 9951, and 9971 supports IEEE 802.3at for
external add-on devices.
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 that runs on your switch supports
your intended phone deployment. See the documentation for your switch for
operating system version information.
Support for NG-PoE+: The Cisco Unified IP Phone 8961, 9951, and 9971 can
draw more power than IEEE 802.3at, as long as there is NG-PoE+ switch
support.
URL
http://www.cisco.com/en/US/products/ps6951/index.html
http://www.cisco.com/en/US/netsol/ns340/ns394/ns147/ns412/
index.html
http://www.cisco.com/en/US/products/hw/switches/index.html
http://www.cisco.com/en/US/products/hw/routers/index.html
http://www.cisco.com/en/US/products/sw/iosswrel/products_
ios_cisco_ios_software_category_home.html
Phone Power Requirements
7