Chapter9 Troubleshooting and Maintenance
CiscoUnified IP Phone Resets Unexpectedly
9-8
Cisco Unified IP Phone 7906G and 7911G Administration Guide for Cisco Unified CallManager
OL-10008-01
Note • When you remove a phone from the CiscoUnified CallManager database, its
configuration file is deleted from the CiscoUnified CallManager TFTP
server. The phone’s directory number or numbers remain in the
Cisco Unified CallManager database. They are called “unassigned DNs” and
can be used for other devices. If unassigned DNs are not used by other
devices, delete them from the Cisco Unified CallManager database. You can
use the Route Plan Report to view and delete unassigned reference numbers.
Refer to Cisco UnifiedCallManager Administration Guide for more
information.
•Changing the buttons on a phone button template, or assigning a different
phone button template to a phone, may result in directory numbers that are no
longer accessible from the phone. The directory numbers are still assigned to
the phone in the Cisco UnifiedCallManager database, but there is no button
on the phone with which calls can be answered. These directory numbers
should be removed from the phone and deleted if necessary.
Cisco Unified IP Phone Resets UnexpectedlyIf 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 CallManager connection are stable, a CiscoUnified 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 CallManager. These sections can help you identify the cause of
a phone resetting in your network:
•Verifying Physical Connection, page9-9
•Identifying Intermittent Network Outages, page9-9
•Verifying DHCP Settings, page9-9
•Checking Static IP Address Settings, page 9-10
•Verifying Voice VLAN Configuration, page9-10
•Verifying that the Phones Have Not Been Intentionally Reset, page9-10
•Eliminating DNS or Other Connectivity Errors, page9-11