Cisco Systems 8.6 manual Understanding Phone Configuration Files

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

Understanding Phone Configuration Files

Obtaining Additional Information about Power

For related information about power, refer to the documents shown in Table 2-2. These documents provide information about the following topics:

•Cisco switches that work with the Cisco Unified IP Phones

•The Cisco IOS releases that support bidirectional power negotiation

•Other requirements and restrictions regarding power

Table 2-2 Related Documentation for Power

Document Topics	URL
Cisco Unified IP Phones Power	http://www.cisco.com/en/US/products/ps6951/index.html
Injector
PoE Solutions	http://www.cisco.com/en/US/netsol/ns340/ns394/ns147/ns412/net
	working_solutions_package.html
Cisco Catalyst Switches	http://www.cisco.com/en/US/products/hw/switches/ps708/tsd_prod
	ucts_support_series_home.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_category_home.html

Understanding Phone Configuration Files

Phone configuration files 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 load 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. 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 Communications Manager 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 to 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 Communications Manager for secure signaling even without the CTL file.

Cisco Unified IP Phone Administration Guide for Cisco Unified Communications Manager 8.6 (SCCP and SIP)

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