Phone Power Requirements - Cisco IP Phone 6851 Administration Manual

Phone Power Requirements

Phone Power Requirements
The Cisco IP Phone 6841 is powered by external power. The Cisco IP Phone 6851 can be powered with
external power or with Power over Ethernet (PoE). A separate power supply provides external power. The
switch can provide PoE through the phone Ethernet cable.
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.
Table 5: Guidelines for Cisco IP Phone Power
Power Type
External power: Provided
through the external power
supply
External power—Provided
through the Cisco IP Phone
Power Injector
PoE power—Provided by a
switch through the Ethernet
cable attached to the Cisco
IP Phone 6851.
The documents in the following table provide more information on the following topics:
• Cisco switches that work with Cisco IP Phones
• Cisco IOS releases that support bidirectional power negotiation
• Other requirements and restrictions about power
Document topics
PoE Solutions
Cisco Catalyst Switches
Cisco IP Phone 6800 Series Multiplatform Phones Administration Guide
14
Guidelines
The Cisco IP Phone 6841 and 6851 use a custom power supply.
The Cisco IP Phone Power Injector may be used with the Cisco IP Phone 6851.
Functioning as a midspan device, the injector delivers inline power to the
attached phone. The Cisco 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.
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.
URL
http://www.cisco.com/c/en/us/solutions/enterprise-networks/
power-over-ethernet-solutions/index.html
http://www.cisco.com/c/en/us/products/switches/index.html