2-5
Cisco Unified IP Phone 6901 and 6911 Administration Guide for Cisco Unified Communications Manager 8.5 (SCCP and SIP)
OL-23874-01
Chapter 2 Preparing to Install the Cisco Unified IP Phone on Your Network
Understanding Phone Configuration Files

Obtaining Additional Information About Power

For related information about power, refer to the documents shown in Table 2-2. These documents
provide information about the following topics:
• Cisco switches that work with the Cisco Unified IP Phone 6901 and 6911
• The Cisco IOS releases that support bidirectional power negotiation
• Other requirements and restrictions regarding power
Understanding Phone Configuration Files
Configuration files for a phone are stored on the TFTP server and define parameters for connecting to
Cisco Unified Communications Manager. In general, any time you make a change in Cisco Unified
Communications Manager 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.
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 Communications Manager, the phone establishes
a TLS connection to Cisco Unified Communications Manager. Otherwise, the phone establishes a TCP
connection.
Note If the device security mode in the configuration file is set to Authenticated or Encrypted, but the phone
has not received a CTL file, the phone tries four times to obtain a CTL file so it can register securely.
If you configure security-related settings in Cisco Unified Communications Manager Administration,
the phone configuration file will contain sensitive information. To ensure the privacy of a configuration
file, you must configure it for encryption. For detailed information, refer to the “Configuring Encrypted
Phone Configuration Files” chapter in Cisco Unified Communications Manager Security Guide. A
phone requests a configuration file whenever it resets and registers with Cisco Unified Communications
Manager.
A phone accesses a default configuration file named XmlDefault.cnf.xml from the TFTP server when
the following conditions exist:
Tab l e 2-2 Related Documentation for Power
Document Topics URL
Cisco Unified IP Phone Power
Injector http://www.cisco.com/en/US/products/ps6951/index.html
PoE Solutions http://www.cisco.com/en/US/netsol/ns340/ns394/ns147/ns412/net
working_solutions_package.html
Cisco Catalyst Switches http://cisco.com/en/US/products/hw/switches/index.html
Integrated Service Routers http://www.cisco.com/en/US/products/hw/routers/index.html
Cisco IOS Software http://www.cisco.com/en/US/products/sw/iosswrel/products_ios_
cisco_ios_software_category_home.html