Mitel 3300 Technician's Handbook page 207

Table 46. Troubleshoot Audio Quality Problems
Symptoms
Echo
Echo
Echo between IP
Phones
Probable cause
Echo Canceller is
beyond specifications.
Network jitter issue.
Layer 2 switch setting
problem.
Troubleshooting
Corrective Action
1.
Identify the path
between the two end
points, and verify if Trunk
is always involved.
2.
Check with Telco to
see if the trunk is within
specs. On a typical T1,
the input signal should be
-15 dbB. If it is too
high(-5 dB for
example),echo may
result.
If this is the case,
keep an echo log to
isolate the problem.
If the problem only
occurs between IP
devices, check
network jitter issue
above.
1.
Check the L2 switch
for duplex mismatch and
spanning tree.
2.
Turn off is possible.
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