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Cisco Unified IP Phone Administration Guide for Cisco Unified Communications Manager 8.6 (SCCP and SIP)
OL-23091-01
Chapter 9 Troubleshooting and Maintenance
Cisco Unified IP Phone Resets Unexpectedly
If the phone is already in the Cisco Unified Communications Manager database, its configuration file
may be damaged. See
Creating a New Configuration File, page 9-5 for assistance.
Symptom: Cisco Unified IP Phone Unable to Obtain IP Address
If a phone is unable to obtain an IP address when it starts up, the phone may be not be on the same
network or VLAN as the DHCP server, or the switch port to which the phone is connected may be
disabled. Make sure that the network or VLAN to which the phone is connected has access to the DHCP
server, and make sure that the switch port is enabled.
Symptom: The Cisco Unified IP Phone Displays the Message Security Error
When a Cisco Unified IP Phone boots, it performs an internal Power On Self Test (POST). POST checks
for existing encryption functionality. If POST detects that encryption functionality is missing, the phone
fails to boot, and the message “Security Error” appears on the screen.
To correct the problem, perform the following steps:
1. Reset the phone manually.
2. If the phone does not start up properly, power up the phone with the handset off-hook. When the
phone is powered up in this way, it attempts to launch a backup software image.
3. If the phone still does not start up properly, perform a factory reset of the phone. For instructions,
see
Performing a Factory Reset, page 9-14.
Cisco Unified IP Phone Resets Unexpectedly
If users report that their phones are resetting during calls or while idle on their desk, you should
investigate the cause. If the network connection and Cisco
Unified Communications Manager
connection are stable, a Cisco
Unified IP Phone should not reset on its own.
Typically, a phone resets if it has problems connecting to the Ethernet network or to Cisco Unified
Communications Manager. These sections can help you identify the cause of a phone resetting in your
network:
• Verifying the Physical Connection, page 9-6
• Identifying Intermittent Network Outages, page 9-7
• Verifying DHCP Settings, page 9-7
• Checking Static IP Address Settings, page 9-7
• Verifying the Voice VLAN Configuration, page 9-7
• Verifying that the Phones Have Not Been Intentionally Reset, page 9-7
• Eliminating DNS or Other Connectivity Errors, page 9-8
Verifying the Physical Connection
Verify that the Ethernet connection to which the Cisco Unified IP Phone is connected is up. For example,
check whether the particular port or switch to which the phone is connected is down and that the switch
is not rebooting. Also make sure that there are no cable breaks.