Power Connection Problems; Audio Problems; No Speech Path; Choppy Speech - Cisco 3905 Administration Manual

Troubleshooting and Maintenance
Solution
If the phone continues to reset, eliminate DNS or other connectivity errors with
Issues, on page 89

Power Connection Problems

Problem
The phone does not appear to be powered up.
Solution
In most cases, a phone restarts if it powers up by using external power but loses that connection and switches
to PoE. Similarly, a phone may restart if it powers up by using PoE and then connects to an external power
supply.

Audio Problems

The following sections describe how to resolve audio problems.

No Speech Path

Problem
One or more people on a call do not hear any audio.
Solution
When at least one person in a call does not receive audio, IP connectivity between phones is not established.
Check the configuration of routers and switches to ensure that IP connectivity is properly configured.

Choppy Speech

Problem
A user complains of choppy speech on a call.
Cause
There may be a mismatch in the jitter configuration.
Solution
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.
Cisco Unified SIP Phone 3905 Administration Guide for Cisco Unified Communications Manager 8.6 (SIP)
Audio Problems
Determine DNS or Connectivity
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