Cisco 7961G Administration Guide

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Cisco IP Phone Administration Guide for Cisco CallManager, Cisco IP Phone 7961G/7961G-GE and 7941G/7941G-GE
OL-6966-01
Chapter 9 Troubleshooting and Maintenance
General Troubleshooting Tips for the Cisco IP Phone
Gaps in voice calls. Check the AvgJtr and the MaxJtr statistics. A large variance
between these statistics might indicate a problem with jitter on
the network or periodic high rates of network activity.
See the “Call Statistics Screen” section on page 7-16 for
information about displaying these statistics.
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 configured.
Table 9-2 Cisco IP Phone Troubleshooting (continued)
Summary Explanation

Cisco 7961G Specifications

General

Brand	Cisco
Model	7961G
Category	IP Phone
Language	English