Cisco 7945G Administration Manual page 172

General Troubleshooting Tips
Table 9-2
Summary
Loopback condition
One-way audio
Peer Firmware Sharing fails.
Cisco VT Advantage/Unified
Video Advantage (CVTA)
Cisco Unified IP Phone 7965G and 7945G Administration Guide for Cisco Unified Communications Manager 6.1(3)
9-12
Cisco Unified IP Phone Troubleshooting (continued)
Explanation
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.
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.
If the Peer Firmware Sharing fails, the phone will default to using the
TFTP server to download firmware. Access the log messages stored
on the remote logging machine to help debug the Peer Firmware
Sharing feature.
These log messages are different than the log messages sent
Note
to the phone log.
If you are having problems getting CVTA to work, make sure that the
PC Port is enabled, and that CDP is enabled on the PC port.
See Network Configuration Menu, page 4-5
Chapter 9 Troubleshooting and Maintenance
for more information.
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