363-206-285 Trouble Clearing: TAP-107
Issue 2, February 2000 Page 22 of 28
DDM-2000 OC-3 MULTIPLEXER
inc. STS1 sig failed (BER) CR or MN For ring applications, the bit error ratio (BER) of the
specified STS-1 signal exceeds the signal fail
threshold (10
–6
). For VT1.5 path-switched rings,
the system responds by inserting VT path AIS in
each pass-through VT contained in the STS-1.
Locally, the system will select the VTs from the
STS-1 on the other ring, as appropriate.
Likely causes: Failure of the near end OLIU circuit
pack reporting the STS-1 failure, failure of the far
end OLIU circuit pack, or failure of the receive fiber
if the OC-3/OC-12 is also reporting a failure.
inc. STS1 unequipped MN The system has detected the unequipped code
(SONET path overhead signal code label byte=0)
on an in-service STS-1 channel.
Likely causes: An upstream STS-1 cross-connect
has been deleted.
inc. STS1 yellow NE ACTY The system has detected an incoming STS-1
yellow signal, which indicates that the far end is
receiving STS-1 AIS on the active OC-3 line. The
system responds to the STS-1 yellow signal by
transmitting DS1 or DS3 yellow toward the DSX.
Likely causes: Incomplete or incorrect
cross-connect provisioning in end-to-end network,
unprotected unidirectional failure of the OLIU
circuit pack, or fiber at some point in the end-to-end
path.
inc. VT AIS CR, MJ,
MN, or
None
The system has detected VT path alarm indication
signal (AIS) incoming from the active OC-3 line.
The system responds by transmitting DS1 AIS
toward the DSX-1 and VT yellow toward the fiber
from which the AIS is being received.
Likely causes: Incomplete or incorrect
cross-connect provisioning in end-to-end network
(In ring applications, this alarm may be caused by
fiber or OLIU circuit pack failures). Unprotected
removal or failure of a DS1 circuit pack at the far
end.
inc. VT LOP MJ or MN The system has detected a VT loss-of-pointer
(LOP) condition.
Likely causes: Unprotected failure of a DS1 circuit
pack at the near end, unprotected failure of a DS1
circuit pack at the far end, unprotected failure of a
MXRVO circuit pack at the near end, or
unprotected failure of a MXRVO circuit pack at the
far end.
Table B – RTRV-ALM Message Descriptions (Continued)
Description
Alarm
Level Meaning
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