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Cisco Unified IP Phone Administration Guide for Cisco Unified CallManager 5.1 (SIP), Cisco Unified IP Phones
OL-11524-01
Chapter9 Troubleshooting and Maintenance
Resetting or Restoring the Cisco Unified IP Phone
Resetting or Restoring the Cisco Unified IP Phone
There are two methods for resetting or restoring the CiscoUnified IP Phone:
•Performing a Basic Reset, page 9-18
•Performing a Factory Reset, page9-19
Loopback condition A loopback condition can occur when the following conditions
are met:
•The SW Port Configuration option in the Network
Configuration menu on the phone is set to 10 Half
(10-BaseT/half duplex)
•The phone receives power from an external power supply.
•The phone is powered down (the power supply is
disconnected).
In this case, the switch port on the phone can become disabled
and the following message will appear in the switch console
log:
HALF_DUX_COLLISION_EXCEED_THRESHOLD
To resolve this problem, re-enable the port from the switch.
One-way audio When at least one person in a call does not receive audio, IP
connectivity between phones is not established. Check the
configurations in routers and switches to ensure that IP
connectivity is properly configures.
Table9-2 Cisco Unified IP Phone Troubleshooting (continued)
Summary Explanation