ACCULINK 336x E1 NTU
4-12
June 1996
3360-A2-GB20-10
Troubleshooting
AT&T Paradyne’s E1 NTU is designed to provide you
with many years of trouble-free service. However,
Table 4-7 gives you some direction if a problem occurs.
For problems other than those listed in the table, please
contact your AT&T Paradyne service representative.
Table 4-7
(1 of 2)
Troubleshooting
Symptom
Possible Cause
Solutions
No power
1. The power module is not securely attached.
2. The wall receptacle has no power.
1. Check the power module attachment.
2. Check the wall receptacle power by plugging
in some equipment that is known to be
working.
Power-Up
Self-Test fails
The E1 NTU has detected an internal hardware
failure.
Contact your AT&T Paradyne field service
representative.
Message LOS on
Loop1 or LOS on
Loop2 appears
1. Network cable problem.
2. The far-end LTU/NTU is not transmitting.
3. Network problem.
1. Check that the network cable is securely
attached at both ends.
2. Check the far-end status.
3. Contact your facility provider.
Message LOS at
DTE appears
1. G.703 DTE cable problem.
2. No signal being transmitted from the DTE.
3. The 120 ohm interface is being used and the
RX SHIELD switch is in the EARTH position.
1. Check that the G.703 DTE cable is securely
attached at both ends.
2. Check the DTE status.
3. Change the RX SHIELD switch to the OPEN
position when using the 120 ohm interface.
Message OOF at
Net appears
1. Incompatible framing format between the
network and the E1 NTU.
2. Network cabling problem.
3. Facility problem.
1. Check that the framing format for the network
interface is correct.
2. Check that the network cable is securely
attached at both ends.
3. Contact your facility provider.
Message OOF at
DTE appears
1. Incompatible framing format between the
G.703 port on the customer premises
equipment and the E1 NTU.
2. G.703 DTE cabling problem.
1. Check that the framing format for the G.703
DTE interface is correct.
2. Check that the G.703 DTE cable is securely
attached at both ends.
Message
RAI at Net
appears
1. Network cable problem.
2. Far-end LTU/NTU has detected an LOS, LOF,
AIS, or EER condition on the line.
3. Facility problem.
1. Check that your network cable is securely
attached at both ends.
2. Check the status of the far-end device.
3. Contact your facility provider.
Message
RAI at DTE
appears
DTE has detected an LOS, LOF, AIS, or EER
condition.
1. Check the status of the DTE.
2. Check that the G.703 DTE cable is securely
attached at both ends.
Message
AIS at Net
appears
1. Upstream LTU/NTU is transmitting an AIS.
2. The network is transmitting an AIS.
1. Check the status of the upstream device(s).
2. Contact your facility provider.