Table 4-3. Messages From The Dsu/Csu - ADTRAN DSU III TDM Manual

Message
LOOP IS
NORMAL
OPEN LOOP
NO RX SIGNAL
OOS/
OOF_FROM NET
CHECK TELCO
LINE
TEST FROM
TELCO
61200063L1-20

Table 4-3. Messages from the DSU/CSU

Meaning
Good local loop
signal being
received from the
telco.
Unit not receiving
a signal from the
telco.
Unit detects
sealing current but
no data signal
from telco.
Unit detects an
Out of Service or
Out of Frame
condition from the
telco.
Transmit/receive
pair reversal
detected.
Telco activated a
loopback to test
the DDS circuit.
DSU III TDM User Manual
Chapter 4. Testing and Troubleshooting
Probable
Cause
Good local loop.
Bad telco cable
from the DSU to
telco jack or bad
circuit to telco.
Bad conductor in
telco cable from
DSU to telco jack
or bad circuit to
telco.
Telco is having
problems with
DDS circuit or
remote unit is
turned off or
disconnected.
Telco wall jack
wired incorrectly.
Telco is testing
circuit.
Action
No action
required; unit
properly
connected to telco
circuit.
Replace telco
cable from DSU to
wall jack. If a
problem persists,
contact telco
provider.
Replace telco
cable from DSU to
wall jack. If a
problem persists,
contact telco
provider.
Check remote
unit. Contact
telco service
provider.
Switch wire pairs
in wall jack or
contact telco
service provider.
Wait until test is
complete or
contact telco
service provider.
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