363-206-295
Maintenance Description
9-16
Issue 1
December 1997
Fault Detection, Isolation, and
Reporting
9
Detection
9
The DDM-2000 OC-12 Multiplexer continuously monitors all circuit packs and
incoming signals for faults. Incoming SONET signals are monitored for loss of
signal (LOS), loss of frame (LOF), loss of pointer (LOP), and bit error ratio (BER)
thresholds, and for the maintenance signals described above. Incoming DS3
signals are monitored for LOS and BER thresholds. The BER thresholds for DS3
are based on bipolar 3-zero substitution (B3ZS) coding violations. The DS3
signals received from the fiber are monitored for AIS and out of frame (OOF)
conditions, unless they are provisioned for clear channel (CC) mode. DS1 timing
references are monitored for AIS, BER, excessive out of frame (EOOF), LOF,
LOS, and out of lock (OOL) conditions.
Isolation
9
When a fault is detected, the DDM-2000 OC-12 Multiplexer uses automatic
diagnostics to isolate the fault to a particular signal or circuit pack.
Reporting
9
The system automatically and autonomously reports all alarm and status
conditions through the appropriate user panel and equipment indicators, office
alarm relays, and through the TL1/X.25 interface. The system stores a record of
all fault conditions and reports them on demand through the CIT and the TL1/X.25
interface. The DDM-2000 OC-12 Multiplexer also stores a history of the past 500
alarm and status conditions and CIT events and reports them on demand through
the CIT interface. Each event is real time and date stamped.
If the diagnostic determines that a circuit pack has failed, the red FAULT LED on
that circuit pack is turned on. If an incoming electrical signal from the DSX fails,
the red FAULT LED on the affected circuit pack flashes on and off in one-second
intervals. A failed incoming optical signal has the same effect.
The DDM-2000 OC-12 Multiplexer provides alarm holdoff and clear delays. The
alarm holdoff delays prevent transient failures from causing unnecessary
maintenance activity. The office alarms are not activated and the OSs are not
notified until a failure lasts at least as long as the alarm holdoff delay. Alarm clear
delays prevent premature clearing of alarms. Alarm indications are not cleared
until a fault condition has been clear for at least as long as the alarm clear delay.
Incoming signal failure conditions, AIS, and FERF signals, are subject to the
Содержание DDM-2000 OC-12
Страница 1: ...363 206 295 Issue 1 December 1997 DDM 2000 OC 12 Multiplexer Release 7 0 User Service Manual Volume I ...
Страница 37: ...Tables xxxviii Issue 1 December 1997 A A SONET Overview A 1 SONET Payloads A 18 A 2 SONET Transport Rates A 19 ...
Страница 506: ...INS PROG 8 of 8 Page INS PROG COMMANDS RELATED rtrv eqpt rtrv ne OC 12 DDM 2000 1997 December 1 Issue 11 89 ...
Страница 528: ...RTRV ATTR ALM 2 of 2 Page RTRV ATTR ALM COMMANDS RELATED set attr alm OC 12 DDM 2000 1997 December 1 Issue 11 111 ...
Страница 565: ...RTRV OC3 3 of 3 Page RTRV OC3 COMMANDS RELATED rtrv sync 11 148 1997 December 1 Issue OC 12 DDM 2000 ...
Страница 664: ...SET FEAT 3 of 3 Page SET FEAT COMMANDS RELATED rtrv feat OC 12 DDM 2000 1997 December 1 Issue 11 247 ...
Страница 766: ... Ctl T TOGGLE 2 of 2 Page Ctl T TOGGLE COMMANDS RELATED logout rlgn OC 12 DDM 2000 1997 December 1 Issue 11 349 ...
Страница 847: ...Multiplexer OC 12 DDM 2000 7 Release TARP TOP Manual User Service II Volume 363 206 295 1 Issue 1997 December ...
Страница 867: ...363 206 295 TOP Maintenance and Operation BLANK LEFT INTENTIONALLY PAGE THIS 12 1997 December 1 Issue ...
Страница 1145: ...Order Circuit 363 206 295 NTP 029 1 of 1 Page 1997 December 1 Issue Unused LISTED ORDER IN BELOW ITEMS DO TO GO DETAILS FOR ...
Страница 1146: ...Order Circuit 363 206 295 NTP 030 1 of 1 Page 1997 December 1 Issue Unused LISTED ORDER IN BELOW ITEMS DO TO GO DETAILS FOR ...
Страница 1182: ...Turnup System 363 206 295 NTP 033 1 of 1 Page 1997 December 1 Issue Unused LISTED ORDER IN BELOW ITEMS DO TO GO DETAILS FOR ...
Страница 1243: ...Clearing Trouble 363 206 295 TAP 107 1 of 1 Page 1997 December 1 Issue Unused ...
Страница 1393: ...363 206 295 DLP 513 1 of 1 Page 1997 December 1 Issue Unused ...
Страница 1394: ...363 206 295 DLP 514 1 of 1 Page 1997 December 1 Issue Unused ...
Страница 1456: ...363 206 295 DLP 523 7 of 7 Page 1997 December 1 Issue OC 12 via Access Broadcast Video for Cross connections of Example 4 Figure ...
Страница 1465: ...DLP 525 363 206 295 1997 December 1 Issue 6 of 2 Page Schematic Ring Virtual ATM Sample 1 Figure ...
Страница 1469: ...DLP 525 363 206 295 1997 December 1 Issue 6 of 6 Page Ring Virtual ATM OC 12 DDM 2000 for Cross connections of Example 4 Figure ...
Страница 1565: ...363 206 295 DLP 543 6 of 5 Page 1997 December 1 Issue Network Broadcast Video of Test Transmission 2 Figure ...
Страница 1566: ...DLP 543 363 206 295 1997 December 1 Issue 6 of 6 Page Network Ring Virtual ATM of Test Transmission 3 Figure ...