Power Outage; Obtaining Additional Information About Power; Understanding Phone Configuration Files - Cisco 6921 Administration Manual

Chapter

Power Outage

Your accessibility to emergency service through the phone is dependent on the phone being powered. If
there is an interruption in the power supply, Service and Emergency Calling Service dialing will not
function until power is restored. In the case of a power failure or disruption, you may need to reset or
reconfigure equipment before using the Service or Emergency Calling Service dialing.

Obtaining Additional Information about Power

For related information about power, refer to the documents shown in
provide information about the following topics:
•
•
•
Table 2-2
Document Topics
Cisco Unified IP Phone Power
Injector
PoE Solutions
Cisco Catalyst Switches
Integrated Service Routers
Cisco IOS Software

Understanding Phone Configuration Files

Configuration files for a phone are stored on the TFTP server and define parameters for connecting to
Cisco Unified CM. In general, any time you make a change in Cisco Unified CM that requires the phone
to be reset, a change is automatically made to the phone's configuration file.
Configuration files also contain information about which image load the phone should be running. If this
image load differs from the one currently loaded on a phone, the phone contacts the TFTP server to
request the required load files.
A phone accesses a default configuration file named XmlDefault.cnf.xml from the TFTP server when
the following conditions exist:
•
•
•
In addition, if the device security mode in the configuration file is set to Authenticated and the CTL file
on the phone has a valid certificate for Cisco Unified CM, the phone establishes a TLS connection to
Cisco Unified CM. Otherwise, the phone establishes a TCP connection.
Cisco Unified IP Phone 6921, 6941, 6945, and 6961 Administration Guide for Cisco Unified Communications Manager 8.6 (SCCP and SIP)
OL-24567-01
Cisco switches that work with the Cisco Unified IP Phone 6921, 6941, 6945, and 6961
The Cisco IOS releases that support bidirectional power negotiation
Other requirements and restrictions regarding power
Related Documentation for Power
You have enabled auto-registration in Cisco Unified CM
The phone has not been added to the Cisco Unified CM database
The phone is registering for the first time
URL
http://www.cisco.com/en/US/products/ps6951/index.html
http://www.cisco.com/en/US/netsol/ns340/ns394/ns147/ns412/inde
x.html
http://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
Understanding Phone Configuration Files
Table 2-2. These documents
2-5