Cisco OL-8148-01 - Manual (Page 8)

Chapter 2 Preparing to Install the Cisco Unified IP Phone on Your Network
Understanding Phone Configuration Files
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Cisco Unified IP Phone Administration Guide for Cisco Unified CallManager 5.0 (SCCP), Cisco Unified IP Phones
OL-8148-01
Understanding Phone Configuration Files
Configuration files for a phone are stored on the TFTP server and define
parameters for connecting to Cisco Unified CallManager. In general, any time you
make a change in Cisco Unified 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.
If you configure security-related settings in Cisco Unified CallManager
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 CallManager Security Guide.
A phone accesses a default configuration file named XmlDefault.cnf.xml from the
TFTP server when these conditions exist:
• You have enabled auto-registration in Cisco Unified CallManager
• The phone has not been added to the Cisco Unified CallManager Database
• The phone is registering for the first time
If auto registration is not enabled and the phone has not been added to the Cisco
Unified CallManager Database, the phone registration request will be rejected. In
this case, the phone will reset and attempt to register repeatedly.
If the phone has registered before, the phone will access the configuration file
named SEPmac_address.cnf.xml, where mac_address is the MAC address of the
phone.