Specifications

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Cisco Unified IP Phone Administration Guide for Cisco Unified Communications Manager 8.5
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Chapter 2 Preparing to Install the Cisco Unified IP Phone on Your Network
Understanding the Phone Startup Process
7. Requesting the ITL file.
The phone requests the ITL file after it requests the CTL
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.
Refer to Cisco Unified Communications Manager
Security Guide, Security by Default.
8. Requesting the Configuration File.
The TFTP server has configuration files, which define
parameters for connecting to Cisco
Unified Communications Manager and other information
for the phone.
See Understanding Phone Configuration Files,
page 2-7.
See Resolving Startup Problems, page 9-1.
9. Contacting Cisco Unified Communications Manager.
The configuration file defines how the Cisco
Unified IP Phone communicates with Cisco
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.
See Understanding Phone Configuration Files,
page 2-7.
See Resolving Startup Problems, page 9-1.
Table 2-4 Cisco Unified IP Phone Startup Process (continued)
Task Purpose Related Topics