Programming instructions

224
3300 ICP Technician’s Handbook
Echo Handsfree
mode is used.
Check if far end is using handsfree. Switch
to handset mode to see if this corrects it,
or lower the volume in handsfree mode.
Echo Canceller
is beyond
specifications.
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 dB. 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.
Network jitter
issue.
If the problem only occurs between IP
devices, check network jitter issue above.
Echo between
IP Phones
Layer 2 switch
setting problem.
1. Check the L2 switch for duplex
mismatch and spanning tree.
2. Turn off spanning tree between the L2
switch and the IP Phone if possible (use
the PortFast setting).
Far end phone
is on handsfree
Check if far end is using handsfree. Switch
to handset mode to see if this corrects it,
or lower the volume in handsfree mode.
In conference
call, echo is
noticed from
external trunk
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 dB. If it is too
high(-5 dB for example), echo may
result. Keep a log to isolate the problem.
There is an
audio path
between the
users as well as
between the
phones.
Provide better acoustic shielding between
users, e.g. close the door, provide
sound-deadening partitions.
Table 29: Audio Quality Problems Troubleshooting (continued)
Symptoms
Probable
cause
Corrective Action
(Page 3 of 3)