Chapter 9 Troubleshooting and Maintenance

 

 

Resetting or Restoring the Cisco Unified IP Phone

 

Table 9-2

Cisco Unified IP Phone Troubleshooting (continued)

 

 

 

 

Summary

 

Explanation

 

 

 

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.

 

 

 

 

Resetting or Restoring the Cisco Unified IP Phone

There are two methods for resetting or restoring the Cisco Unified IP Phone:

Performing a Basic Reset, page 9-18

Performing a Factory Reset, page 9-19

Cisco Unified IP Phone Administration Guide for Cisco Unified CallManager 5.1 (SIP), Cisco Unified IP Phones

 

OL-11524-01

9-17

 

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Cisco Systems 7970G manual Halfduxcollisionexceedthreshold, Performing a Basic Reset, Performing a Factory Reset