Cisco CP-3911 - Unified SIP Phone 3911 VoIP Administration Manual page 89

Chapter 7 Troubleshooting and Maintenance
Table 7-1 Cisco Unified IP Phone Troubleshooting (continued)
Summary
Moving a network connection from
the phone to a workstation.
Changing the telephone
configuration.
Phone resetting.
LCD display issues.
Dual-Tone Multi-Frequency (DTMF)
delay.
Cisco Unified SIP Phone 3911 Administration Guide for Cisco Unified Communications Manager
OL-14029-01
General Troubleshooting Tips for the Cisco Unified IP Phone
Explanation
If you are powering your phone through the network
connection, you must be careful if you decide to unplug the
phone's network connection and plug the cable into a desktop
computer.
The computer's network card cannot receive power
Caution
through the network connection; if power comes
through the connection, the network card can be
destroyed. To protect a network card, wait 10
seconds or longer after unplugging the cable from
the phone before plugging it into a computer. This
delay gives the switch enough time to recognize that
there is no longer a phone on the line and to stop
providing power to the cable.
By default, the network configuration options are locked to
prevent users from making changes that could impact their
network connectivity. You must unlock the network
configuration options before you can configure them. See the
"Unlocking and Locking Options" section on page 4-2
details.
The phone resets when it loses contact with the Cisco Unified
Communications Manager software. This lost connection can
be due to any network connectivity disruption, including cable
breaks, switch outages, and switch reboots.
If the display appears to have rolling lines or a wavy pattern, it
might be interacting with certain types of older fluorescent
lights in the building. Moving the phone away from the lights,
or replacing the lights, should resolve the problem.
When you are on a call that requires keypad input, if you press
the keys too quickly, some of them might not be recognized.
for
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