Specifications

2-4
Cisco Unified IP Phone 7906G and 7911G for Cisco Unified Communications Manager 8.0
OL-21033-01
Chapter 2 Preparing to Install the Cisco Unified IP Phone on Your Network
Understanding Phone Configuration Files
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 Table 2-2. These documents
provide information about these topics:
• Cisco switches that work with the Cisco Unified IP Phones 7906G and 7911G
• 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. These files are digitally signed to ensure the authenticity of the files’
source.
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 Administration. Otherwise, the phone
establishes a TCP connection.
Table 2-2 Related Documentation for Power
Document Topics URL
Cisco Unified IP Phone Power
Injector
http://www.cisco.com/en/US/products/hw/phones/ps379/prod_installation_guides_list.htm
l
PoE Solutions http://www.cisco.com/en/US/netsol/ns340/ns394/ns147/ns412/networking_solutions_pack
age.html
Cisco Catalyst Switches http://www.cisco.com/en/US/products/hw/switches/ps708/tsd_products_support_series_ho
me.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_cate
gory_home.html