Cisco Systems OL-23092-01 manual Security Guide, Security by Default

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

Understanding the Phone Startup Process

Table 2-4	Cisco Unified IP Phone Startup Process (continued)
Task	Purpose	Related Topics
7.	Requesting the ITL file.	Refer to Cisco Unified Communications Manager
	The phone requests the ITL file after it requests the CTL	Security Guide, Security by Default.
	file. The ITL file contains the certificates of the entities that
	the phone can trust. The certificates are used for
	authenticating a secure connection with the servers or
	authenticating a digital signature signed by the servers.
8.	Requesting the Configuration File.	See Understanding Phone Configuration Files,
	The TFTP server has configuration files, which define	page 2-7.
	parameters for connecting to Cisco	See Resolving Startup Problems, page 9-1.
	Unified Communications Manager and other information
	for the phone.
9.	Contacting Cisco Unified Communications Manager.	See Understanding Phone Configuration Files,
	The configuration file defines how the Cisco	page 2-7.
	Unified IP Phone communicates with Cisco	See Resolving Startup Problems, page 9-1.
	Unified Communications Manager and provides a phone
	with its load ID. After obtaining the file from the TFTP
	server, the phone attempts to make a connection to the
	highest priority Cisco Unified Communications Manager
	on the list. If the security profile of the phone is configured
	for secure signaling (encrypted or authenticated), and the
	Cisco Unified Communications Manager is set to secure
	mode, the phone makes a TLS connection. Otherwise, it
	makes a nonsecure TCP connection.
	If the phone was manually added to the database, Cisco
	Unified Communications Manager identifies the phone. If
	the phone was not manually added to the database and
	auto-registration is enabled in Cisco
	Unified Communications Manager, the phone attempts to
	auto-register itself in the Cisco Unified Communications
	Manager database.
	Note Auto-registration is disabled when you configure
	the CTL client. In this case, the phone must be
	manually added to the Cisco Unified
	Communications Manager database.

	Cisco Unified IP Phone Administration Guide for Cisco Unified Communications Manager 8.5
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