Mitel SX-200 ICP - 1.0 5020, Technician'S Handbook

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Advanced Troubleshooting and Repair
Broken Audio,
intermittent (IP trunks
only) Handsfree on the far
end. Ensure that neither device is using
Handsfree. Some handsfree phones
only operate at half duplex.
Packet loss, jitter via
network. 1. Identify the speech path between
the two end points, including
router, switch WAN in the audio
stream.
2. The network administrator needs
to apply QOS/TOS to minimize
jitter over slow speed interface
(T1, Frame Relay, etc.), and give
voice traffic priority over data.
Limited bandwidth and
too many calls across
router, or combination
data and voice. 1. Limit the number of calls to remote
subnets.
2. The network administrator needs
to apply QOS/TOS to give voice
traffic priority over data.
Physical port error
(CRC, faulty cable,
duplex mismatch, HUB). 1. Identify the speech path between
the two end points, including
router, switch WAN in the audio
stream.
2. Verify that there is no duplex
mismatch in each port settings
and/or faulty cable, or faulty port.
3. Make sure that the IP Phone is not
plugged into a HUB.
Compression enabled Compression will save bandwidth,
but may cause noticeable clipping. If
not sure, disable compression to see
if it makes a difference.
Router’s CPU is
exhausted or congested. Router may be running excessive
filtering. The network administrator
may need to monitor the
performance of the router.
Echo between IP
Phones Layer 2 switch setting
problem. 1. Check the L2 switch for duplex
mismatch and spanning tree.
2. Turn off if possible.
Table 47: Audio Quality Problems Troubleshooting (continued)
Symptoms Probable Cause Corrective Action
(Page 2 of 2)