Configuration Files; Phone Startup Process - Cisco 3905 Administration Manual

Cisco Unified IP Phone and Your Network

Configuration Files

Configuration files for a phone 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 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.
If you configure security-related settings in Cisco Unified Communications Manager Administration, the
phone configuration file will contain sensitive information. To ensure the privacy of a configuration file, you
must configure it for encryption. For more information, see the "Configuring Encrypted Phone Configuration
Files" chapter in Cisco Unified Communications Manager Security Guide. A phone requests a configuration
file whenever it resets and registers with Cisco Unified Communications Manager.
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 Cisco Unified Communications Manager
• The phone has not been added to the Cisco Unified Communications Manager 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 Communications
Manager database, the phone registration request will be rejected.
For more information on phone configuration settings, see the "Cisco Unified IP Phone Configuration" chapter
in the Cisco Unified Communications Manager Administration Guide.

Phone Startup Process

When connecting to the VoIP network, the Cisco Unified SIP Phone 3905 go through a standard startup
process that is described in the following table. Depending on your specific network configuration, not all of
these steps may occur on your Cisco Unified IP Phone.
Procedure
Step 1
Obtain power from the Switch. If a phone is not using external power, the switch provides in-line power
through the Ethernet cable attached to the phone.
For more information, see
and Startup Problems, on page
Step 2 Configure the VLAN. If the Cisco Unified IP Phone is connected to a Cisco Catalyst switch, the switch next
informs the phone of the voice VLAN defined on the switch. The phone needs to know its VLAN membership
before it can proceed with the Dynamic Host Configuration Protocol (DHCP) request for an IP address.
For more information, see
Step 3
Obtain an IP Address. If the Cisco Unified IP Phone is using DHCP to obtain an IP address, the phone queries
the DHCP server to obtain one. If you are not using DHCP in your network, you must assign static IP addresses
to each phone locally.
Cisco Unified Communications Manager Phone Addition Methods, on page 26
79.
Configuration Menus, on page 35
Cisco Unified SIP Phone 3905 Administration Guide for Cisco Unified Communications Manager 8.6 (SIP)
Configuration Files
and Startup Problems, on page 79.
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