Chapter 9 Troubleshooting and Maintenance
General Troubleshooting Tips
9-18
Cisco Unified IP Phone 7970G/7971G-GE Administration Guide for Cisco Unified Communications Manager 6.1
OL-14626-01
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_THRESHO
LD
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.
Peer to peer image
distribution fails.
If the peer to peer image distribution 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 to
peer image distribution feature.
Note
These log messages are different than the log
messages sent to the
phone log.
Cisco VT Advantage/
Unified Video Advantage
(CVTA)
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.
Table 9-2
Cisco Unified IP Phone Troubleshooting (continued)
Summary
Explanation
Summary of Contents for 7970G - IP Phone VoIP
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