Lucent Technologies DDM-2000 OC-3, User & Service Manual

Page: 1965 / 2536

TAP-107
: Trouble Clearing 363-206-285
Page 9 of 28 Issue 2, February 2000
DDM-2000 OC-3 M
ULTIPLEXER
forced switch
ABN When associated with an OC-3 line, this message
means that the identified line is not selected as the
active receiving line, and an automatic or manual
protection switch to make this the active receiving
line will not be done. The forced switch will remain
in effect until the protection switch is reset, or a
lockout or inhibit switch request is received.
Note: OC-3 line switching is unidirectional.
Because of this, the specified OC-3 line might still
be active (if the far end is selecting the specified
line to receive traffic), and the far end might still be
free to switch the line it is selecting to receive
traffic. (See the
switch-line:
command.)
When associated with a FUNCTION UNITS slot or
a LOW SPEED service slot, this message means
that the identified equipment is not active, and an
automatic or manual switch to make it active will
not be done. The forced switch will remain in effect
until the protection switch is reset, or a lockout or
inhibit switch request is received. (See the
switch-fn:
and
switch-ls:
commands.)
frequency error
MJ This alarm condition indicates that an incoming
timing signal has an unacceptable frequency offset.
Likely causes: A DS1 external timing reference to
the local shelf or a remote shelf has a frequency
offset greater than about 20 hertz.
holdover mode active
NE ACTY System is in holdover synchronization mode.
Likely causes: System was manually switched to
holdover mode (with
switch-sync:
command or
in a central office system, with TBOS control point
54) and switch has not been reset; or the system
automatically switched to holdover mode due to
failure of timing references, and either
(1) the reference failures have not cleared, or
(2) the system is provisioned for nonrevertive
synchronization mode switching, or
(3) the system is provisioned for
External
timing
and no external timing references are available, or
(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) or
Table B – RTRV-ALM Message Descriptions (Continued)
Description
Alarm
Level
Meaning