TAP-117: Trouble Clearing 363-206-285
Page 3 of 4 Issue 2, February 2000
DDM-2000 OC-3 MULTIPLEXER
TableA–AlarmandStatus-NEACTY
Activity Meaning
holdover mode active System is in holdover synchronization mode.
Likely causes:
A. The system was manually switched to holdover mode (with
switch-sync: command) and switch has not been reset. or the
system automatically
B. The system automatically switched to holdover mode due to
failure of timing references, as follows:
(1) The reference failures have not cleared.
(2) The system is provisioned for nonrevertive synchronization
mode switching.
(3) The system is provisioned for External timing and no external
timing references are available.
(4) The system is provisioned for loop-timed operation and the
optical line or OLIU circuit pack has failed, or a message indicating
an upstream clock problem has been received on the sync
message bits of the optical line (rtrv-sync: command).
(5) The system is provisioned for sync message signaling, but the
upstream system from which it loop-times has not been
provisioned for sync message signaling. The condition can be
cleared by provisioning both systems the same (set-sync: and
rtrv-sync: commands). The condition can be cleared by
repairing at least one of timing references (if both are failed) and
resetting synchronization mode protection switch with command
switch-sync:s=mode,pri=reset.
inc. OC1 line AIS The system detects inc. OC-1 line AIS on active incoming OC-1
line.
Likely cause: Failure of OLIU circuit pack at far end [TAP-119].
inc. (from DSX) DS3 AIS The system has detected DS3 AIS in the MUX direction (coming
from DSX-3) for the specified DS3 signal. This alarm is applicable
to the BBG20 TMUX circuit pack only.
Likely causes: The incoming DS3 signal at the far end has failed.
inc. (from fiber) DS3
AIS
The system has detected DS3 AIS in the DEMUX direction (coming
from the fiber) for the specified DS3 signal.
Likely causes: The incoming DS3 signal at the far end has failed,
DS3 AIS is received from the DSX-3 at the far end, or incomplete
or missing STS1 (DS3) cross-connections at a far end terminal.
Check incoming DS3 signal at far end and/or look for missing
cross-connections [TAP-120].
inc. (from DSX) DS3 OOF The system detects a DS3 out-of-frame condition in MUX direction
(coming from DSX-3) for the specified DS3 signal. This alarm is
applicable to the BBG20 TMUX circuit pack only.
Likely causes: An OOF DS3 signal inc. to the DSX-3 at the far
end.
To Next Page
Loading...
Need help?
General
