Chapter2 Preparing to Install the Cisco Unified IP Phone on You r Network
Understanding Phone Configuration Files
2-6
Cisco Unified IP Phone 7906G and 7911G Administration Guide for Cisco Unified CallManager
OL-10008-01
Understanding Phone Configuration FilesConfiguration files for a phone are stored on the TFTP server and define
parameters for connecting to Cisco UnifiedCallManager. In general, any time
you make a change in CiscoUnified CallManager that requires the phone to be
reset, a change is made to the phone’s configuration file automatically.
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 CallManager, the phone establishes a TLS connection to
Cisco Unified CallManager. 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 will continuously
try to obtain a CTL file so that it can register securely.
A phone requests a configuration file whenever it resets and registers with
Cisco Unified CallManager.
Table2-2 Related Documentation for Power
Document Topics URL
PoE Solutions http://www.cisco.com/en/US/netsol/
ns340/ns394/ns147/ns412/networking
_solutions_package.html
Cisco Catalyst Switches http://www.cisco.com/univercd/cc/td/
doc/product/lan/index.htm
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