Chapter2 Preparing to Install the Cisco Unified IP Phone o n Your Network
Understanding Phone Configuration Files
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Cisco Unified IP Phone Administration Guide for Cisco Unified CallManager 5.1 (SIP), Cisco Unified IP Phones
OL-11524-01
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.
The transport protocol in the configuration file must also be set to TLS
(corresponding to the transport type in the SIP Security Profile on CiscoUnified
CallManager).
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.
A phone accesses a default configuration file named XmlDefault.cnf.xml from the
TFTP server when the following conditions exist:
•You have enabled auto-registration in CiscoUnified 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.