Understanding Phone Configuration Files | Cisco Systems OL-23089-01

Chapter 2 Preparing to Install the Cisco Unified IP Phone on Your Network

Understanding Phone Configuration Files

Configuration files for a phone are stored on the TFTP server and define parameters for connecting to Cisco Unified CM. In general, any time you make a change in Cisco Unified CM that requires the phone to be reset, a change is made automatically to the phone 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 that is loaded on a phone currently, the phone contacts the TFTP server to request the required load files. (These files are digitally signed to ensure the authenticity of the file 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 CM, the phone establishes a TLS connection to Cisco Unified CM. Otherwise, the phone establishes a TCP connection. For SIP phones, a TLS connection requires that the transport protocol in the phone configuration file be set to TLS, which corresponds to the transport type in the SIP Security Profile in Cisco Unified CM Administration.

Note If the device security mode in the configuration file is set to Authenticated or Encrypted, but the phone has not received a CTL or ITL file, the phone tries four times obtain the file so it can register securely.

Note Cisco Extension Mobility Cross Cluster is an exception, in that the phone permits a TLS connection to Cisco Unified CM for secure signaling even without the CTL file.

If you configure security-related settings in Cisco Unified CM 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, see the Cisco Unified Communications Manager Security Guide, Configuring Encrypted Phone Configuration Files.

A phone accesses a default configuration file named XmlDefault.cnf.xml only when the phone has not received a valid Trust List file containing a certificate assigned to the Cisco Unified CM and TFTP.

If auto registration is not enabled and you did not add the phone to the Cisco Unified CM database, the phone does not attempt to register with Cisco Unified CM. The phone continually displays the “Configuring IP” message until you either enable auto-registration or add the phone to the Cisco Unified CM database.

If the phone has registered before, the phone accesses the configuration file named

SEPmac_address.cnf.xml, where mac_address is the MAC address of the phone.

For SIP phones, the TFTP server generates these SIP configuration files:

•SIP IP Phone:

–For unsigned and unencrypted files—SEP<mac>.cnf.xml

–For signed files—SEP<mac>.cnf.xml.sgn

–For signed and encrypted files—SEP<mac>.cnf.xml.enc.sgn

•Dial Plan—<dialplan>.xml

•Softkey Template—<softkey_template>.xml

The filenames are derived from the MAC Address and Description fields in the Phone Configuration window of Cisco Unified CM. The MAC address uniquely identifies the phone. For more information, see the Cisco Unified Communications Manager Administration Guide.

Cisco Unified IP Phone 7931G Administration Guide for Cisco Unified Communications Manager 8.5 (SCCP and SIP)

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