optix alarms
DESCRIPTION
OPTIX ALARMSTRANSCRIPT
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Internal
OTA105210 OptiX NG-SDH Alarm and Performance Event
ISSUE 1.02
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Upon completion of this course, you will be able to:
Know the mechanism of SDH Alarm and performance
generation;
Analyze and process most of common alarm and
performance events.
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Chapter 1 Generation of Alarm & PerformanceChapter 1 Generation of Alarm & Performance
Chapter 2 Alarm & Performance Event ClearingChapter 2 Alarm & Performance Event Clearing
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Chapter 1 Generation of Alarm& PerformanceChapter 1 Generation of Alarm& Performance
1.1 Terminology 1.1 Terminology
1.2 1.2 Higher Order PartHigher Order Part
1.3 Lower Order Part1.3 Lower Order Part
1.4 Suppression Correlation between 1.4 Suppression Correlation between
SDH AlarmsSDH Alarms
1.5 Generation and Detection of SDH 1.5 Generation and Detection of SDH
Performance EventsPerformance Events
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Terminology
SDHInterface cross-connect
unit
SDHInterface
PDH interface
Higher order part
Downlink signal flow
Downlink signal flow & Higher order partDownlink signal flow & Higher order part
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Terminology
SDHInterface cross-connect
unit
SDHInterface
PDH interface
Lower order part
Uplink signal flow & Lower order partUplink signal flow & Lower order part
Uplink signal flow
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Terminology
Two Common AlarmsTwo Common Alarms
AIS (Alarm Indication Signal)
Inserts the all “1”s signal into the lower level circuits, Indicating
that the signal is
unavailable. Common AIS alarms include MS_AIS, AU_AIS,
TU_AIS and E1_AIS.
RDI (Remote Defect Indication)
Indicates the alarm transferred back to the home station from the
opposite station after the opposite station has detected alarms of
LOS (loss of signal), AIS and TIM (trace identifier mismatch).
Common RDI alarms include MS_RDI, HP_RDI and LP_RDI.
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Chapter 1 Generation of Alarm& PerformanceChapter 1 Generation of Alarm& Performance
1.1 Terminology1.1 Terminology
1.2 1.2 Higher Order PartHigher Order Part
1.3 Lower Order Part1.3 Lower Order Part
1.4 Suppression Correlation between 1.4 Suppression Correlation between
SDH AlarmsSDH Alarms
1.5 Generation and Detection of SDH 1.5 Generation and Detection of SDH
Performance EventsPerformance Events
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A B C D E F G
STM-N Cross-connect Unit
SPISPI RSTRST MSTMST MSPMSP MSAMSA HPTHPT
Uplink signal Flow
Downlink signal Flow
SDH Interface to Cross-connect UnitSDH Interface to Cross-connect Unit
Alarms & Performance of Higher Order Part
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Frame synchronizer& RS overhead processor
(RST)
MS overhead processor
(MST)
Pointer processor& HP overhead processor
(MSA, HPT)
LOS
LOF
B1 ErrA1,A2
B1
AIS
MS_AIS
B2 ErrK2B2
MS_REIM1
MS_RDIK2
“1” AIS
AU_AIS
AU_LOPH1,H2
H4B3 Err
J1
HP_SLMC2
“1”
HP_LOM
HP_TIMHP_UNEQ
HP_REI
HP_RDI
H1,H2
C2
B3
G1
G1
“1” XCS
STM-N
Optical Signal
Downlink signal flow Alarm report or returnSignal transfer point (Insert down all
"1"s signal)Alarm termination point
(Report to SCC unit)
Alarms & Performance of Higher Order Part
Diagram of Alarm GenerationDiagram of Alarm Generation
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Downlink Signal FlowDownlink Signal Flow
Frame synchronizer and RS overhead processor Optical receiving
Optical/electrical conversion (O/E) O/E module checks Optical signal (If no light in the input signal, optical power
excessively low or high or the code type mismatch, R_LOS alarm will be reported)
A1, A2 and J0 bytes detecting Search the framing bytes (R_OOF, R_LOF) Extract the line synchronous timing source J0 byte (J0_MM) Scramble
B1 byte detecting BIP-8 computing to check bit error (B1_SD, B1_EXC, SES, RSUAT) Process F1, D1 - D3 and E1 bytes
Alarms& Performance of Higher Order Part
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Downlink Signal FlowDownlink Signal Flow
MS overhead processor
K1 and K2 bytes detecting
SF and SD detection
Process D4 ~ D12, S1 and E2 bytes
MSP protection function
MS_AIS, MS_RDI
B2 byte detecting
BIP-24 computing to check bit error (B2_SD and B2_OVER)
M1 bytes (MS_REI)
Alarms& Performance of Higher Order Part
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Downlink Signal FlowDownlink Signal Flow
Pointer processor and HP overhead processor H1 and H2 bytes detecting
Frequency and phase alignment Locate each VC-4 and send it to higher order path overhead processor Generate AU_AIS, AU_LOP
J1, C2, B3 and G1 bytes detecting J1 Bytes (HP_TIM) C2 Bytes (HP_UNEQ, HP_SLM) B3 bit error detecting (B3_SD, B3_OVER, SES, HVCUAT) H4 Bytes (For VC12 signal, HP_LOM) G1 Bytes (HP_RDI, HP_REI) F3, K3, N1 Bytes (Reserved)
Alarms& Performance of Higher Order Part
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Uplink Signal FlowUplink Signal Flow
Pointer processor and HP overhead processor
Generates N higher order path overhead bytes
J1, C2, B3, G1, F2, F3 and N1 Bytes
Return alarm to the remote end
HP_RDI (G1)
HP_REI (G1)
AU-4 pointers generating
Pointer processor generates N AU-4 pointers
Alarms& Performance of Higher Order Part
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Uplink Signal FlowUplink Signal Flow
Alarms& Performance of Higher Order Part
MS overhead processor
Set multiplex section overhead (MSOH) Bytes
K1, K2, D4-D12, S1, M1, E2 and B2 Bytes
Return alarm to the remote end
MS_RDI (K2)
MS_REI (M1)
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Uplink Signal FlowUplink Signal Flow
Alarms& Performance of Higher Order Part
Frame synchronizer and RS overhead processor
Set regenerator section overhead (RSOH) Bytes
A1, A2, J0, E1, F1, D1-D3 and B1 Bytes
Frame synchronizer and scrambler scrambles STM-N electrical
signals
E/O
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Chapter 1 Generation of Alarm& PerformanceChapter 1 Generation of Alarm& Performance
1.1 Terminology1.1 Terminology
1.2 1.2 Higher Order PartHigher Order Part
1.3 Lower Order Part1.3 Lower Order Part
1.4 Suppression Correlation between 1.4 Suppression Correlation between
SDH AlarmsSDH Alarms
1.5 Generation and Detection of SDH 1.5 Generation and Detection of SDH
Performance EventsPerformance Events
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G H I J K
PDH InterfaceCross-connect Unit
HPAHPA LPTLPT LPALPA PPIPPI
Uplink signal Flow
Downlink signal Flow
PDH Interface to Cross-connect UnitPDH Interface to Cross-connect Unit
Alarms & Performance of Lower Order Part
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PDH Physical InterfaceLower Order Path AdaptationHigher Order Path Adaptation& Lower Order Path Termination
E1 Interface
E1 Interface
Diagram of Alarm GenerationDiagram of Alarm Generation
(PPI)(LPA)(HPA, LPT)
LP_TFIFO
All “1”
LP_SLM
LP_UNEQ
V1,V2
H4
BIP 2
J2
TU_AIS
V5
HP_LOM
LP_TIMTU_LOP
LP_REI
LP_RDI
V5
V5
XCS
V5
V1,V2
LP_RFIFO
E1_AIS All “1” T_ALOS
E1_AISXCS
Downlink signal flow Alarm report or returnSignal transfer point (Insert down all
"1"s signal)Alarm termination point (Report
to SCC unit)
Alarms & Performance of Lower Order Part
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Downlink Signal FlowDownlink Signal Flow
Alarms & Performance of Lower Order Part
V1, V2 and V3 bytes detecting
Demap the VC-4 into VC-12s
Pointers of all VC-12s are decoded
TU_AIS, TU_LOP
V5 Bytes detecting
LP_RDI( b8), LP_UNEQ, LP_SLM( b5-b7), LP_REI( b3)
BIP-2 computing to check bit error( b1-b2)
H4 Bytes detecting
HP_LOM
J2 Bytes detecting
LP_TIM
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Downlink Signal FlowDownlink Signal Flow
Lower Order Path Adaptation& PDH Physical Interface
Lower Order Path Adaptation
Recover data stream and the related clock reference signals
Detect LP_RFIFO alarm
PDH Physical Interface
Forming a 2048 kbit/s signal
Alarms & Performance of Lower Order Part
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Uplink Signal FlowUplink Signal Flow
Lower Order Path Adaptation& PDH Physical Interface
Lower Order Path Adaptation
Data adaptation
Detect LP_TFIFO alarm
PDH Physical Interface
Clock extraction and dada regeneration
Detect and terminate the T_ALOS alarm
Detect E1_AIS alarm
Alarms & Performance of Lower Order Part
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Uplink Signal FlowUplink Signal Flow
Higher Order Path Adaptation& Lower Order Path Termination
Lower Order Path Termination
Insert POH in the C-12 (C-12 to VC-12)
V5 byte (Insert "signal label" in the b5-b7, calculate BIP-2, set the result to the b1 and
b2)
Higher Order Path Adaptation
Adapt VC-12 into TU-12
Map TU-12 into higher order VC-4
Alarms & Performance of Lower Order Part
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Difference between E3/E4 and E1 Alarm Signal
For E3 and E4 PDH services, the flow of signal processing is the same as that
of E1 PDH service But there are still some differences:
Same Type of Alarms with Different Names
2Mbit/s : T_ALOS TU_AIS
34Mbit/s : P_LOS E3_AIS
140Mbit/s : EXT_LOS C4_R_LAISD/C4_T_LAISD
Path Overhead Bytes Used for Alarm& Performance Monitoring are Differe
nt
2Mbit/s: V5 Byte
34Mbit/s, 140Mbit/s: B3, J1, C2 and G1 Bytes
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Chapter 1 Generation of Alarm& PerformanceChapter 1 Generation of Alarm& Performance
1.1 Terminology1.1 Terminology
1.2 1.2 Higher Order PartHigher Order Part
1.3 Lower Order Part1.3 Lower Order Part
1.4 Suppression Correlation between 1.4 Suppression Correlation between
SDH AlarmsSDH Alarms
1.5 Generation and Detection of SDH 1.5 Generation and Detection of SDH
Performance EventsPerformance Events
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R_LOS
R_LOF
R_OOF
AU_AIS AU_LOP
B1_SD B2_SD
HP_TIM HP_SLM HP_LOM HP_UNEQB3_EXEC
B3_SD TU_AIS TU_LOP
BIP_EXEC
LP_UNEQ LP_TIM LP_SLM
BIP_SD
MS_RDI
HP_RDI
LP_RDI
Legend:
A B A suppress B
J0_MM MS_AIS B1_EXEC B2_EXEC
A1, A2 Bytes
RSOH, MSOH (Except A1,A2)
Suppression Correlation between SDH Alarms
Suppression Relationship
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Chapter 1 Generation of Alarm& PerformanceChapter 1 Generation of Alarm& Performance
1.1 Terminology1.1 Terminology
1.2 1.2 Higher Order PartHigher Order Part
1.3 Lower Order Part1.3 Lower Order Part
1.4 Suppression Correlation between 1.4 Suppression Correlation between
SDH AlarmsSDH Alarms
1.5 Generation and Detection of SDH1.5 Generation and Detection of SDH
Performance EventsPerformance Events
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Bit Error Generation MechanismBit Error Generation Mechanism
Notice: The Sequence of descramble& BIPNotice: The Sequence of descramble& BIP
Generation and Detection of SDH Performance
Mechanism: Bit interleaved parity (BIP)
Transmit end: The result of BIP is placed in the relevant bytes of the
next frame
Receive end: Compare the result of BIP with the bytes of the next
frame
B1: BIP8 for the regenerator section error monitoring function
B2: BIP24 for multiplex section error monitoring function
B3: BIP8 for monitoring the bit error performance of VC-4
V5: BIP2 for monitoring the bit error performance of VC-12
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B1
B2
B3
V5
RSTMSTHPTLPT LPTHPTMSTRST
Error Detection and ReportError Detection and Report
Generation and Detection of SDH Performance
Errors occurring in lower order path will not be detected in higher order
path, higher order bit errors will trigger lower order errors.
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TermsTerms
Generation and Detection of SDH Performance
Term Description
BE Errored block, in which one or more bits are in error.
BBE Background block error, it is an errored block occurring outside of the period of UAT and SES.
FEBBE Far end block of background error, it is a BBE event detected at the far end.
ES Errored second, it is a certain second with one or more errored blocks detected.
FEES Far end errored second, in which an ES event detected at the far end.
SES
Severely errored second, it is a certain second which contains 30% errored blocks or at least one serious disturbance period (SDP). Here, the SDP is a period of at least four consecutive blocks or 1ms (taking the longer one) where the error ratios of all the consecutive blocks are 10-2 or loss of signal occurs.
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TermsTerms
Generation and Detection of SDH Performance
Term Description
FESES Far end severely errored second, in which an SES event det
ected at the remote end.
CSES Consecutive severely errored second, in which the SES eve
nts consecutively occur, but last less than 10 seconds.
FECSES Far end consecutive severely errored second, in which a CS
ES event detected at the far end.
UAS
Unavailable second, it is a period of 10 consecutive
seconds during which the bit error ratio per second of the
digital signal in either of the transmission directions of a
transmission system is inferior to 10-3 . These ten seconds
are considered to be part of unavailable time.
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Generation and Detection of SDH Performance
Mechanism
Adjust pointers as required in practice, so as to tolerate rate asyn
chronization and phase difference of payload signals. That is, per
form pointer justification on information payloads to make the pay
loads synchronous with the STM-N frame
Sort
Administrative unit pointer (AU_PTR)
Tributary unit pointer (TU_PTR)
PointerPointer JustificationJustification
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Generation and Detection of SDH Performance
H1 Y Y H2 F F H3 H3 H3 VC4
9
row
10………270 Column
91
Location:
Causation:
− Network is out of synchronization
Pointer justification state:
NameByte numbering and content of the fourth row in STM-1 frame
Rate relation
7 8 9 10 11 12
Zero H3 H3 H3 Info Info Info Information = container
Positive H3 H3 H3 Stuffing Stuffing Stuffing Information< container
Negative Info Info Info Info Info Info Information> container
GenerationGeneration MechanismMechanism of AU Pointer Justificationof AU Pointer Justification
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Causation:
− Transformed from AU pointer justification
− The system clock is not consistent with the received clock
− Pointer justification occurs at the upstream NE where the service passes
Generation and Detection of SDH Performance
Remote detection:
− Occur at the local station, report at the remote station
Local detection:
− Generate at the local station, report locally
Generation Mechanism of TU Pointer JustificationGeneration Mechanism of TU Pointer Justification
Detection and Reporting of Pointer JustificationDetection and Reporting of Pointer Justification
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Relationship between Alarms and Performance
Relationship
Alarm and Performance are belong to different levels. Alarm indicates the
fault of transmission, performance indicates the signal degrade of
transmission. If the value of performance is high than threshold it will
translate into alarm. For example bit error can translate into EXC alarm then
causes the traffic interrupt.
Functions of alarm and performance for bit error threshold crossing
Item Performance Event Alarm Event
Local end Remote end Local end Remote endRS RSBBE - B1_OVER -
MS MSBBE MSFEBBE B2_OVER MS_REI
HP HPBBE HPFEBBE HPCROSSTR HP_REI
LP LPBBE LPFEBBE LPCROSSTR LP_REI
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Question
Please describe the suppression correlation between SDH alarms?
What’s the mechanism of Pointer justification?
What’s the relationship between Performance event and Alarm?
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Chapter 1 Generation of Alarm& PerformanceChapter 1 Generation of Alarm& Performance
Chapter 2 Alarm& Performance Event ClearingChapter 2 Alarm& Performance Event Clearing
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Chapter 2 Chapter 2 Alarm& Performance Event ClearingAlarm& Performance Event Clearing
2.1 SDH Unit 2.1 SDH Unit
2.2 2.2 PDH UnitPDH Unit
2.3 Ethernet Unit2.3 Ethernet Unit
2.4 Cross-connect and timing Unit2.4 Cross-connect and timing Unit
2.5 SCC Unit2.5 SCC Unit
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SDH Unit
R_LOF
Introduction:
− R_LOF alarm indicates “receive loss of frame”, critical alarm.
Probable Causes:
− The received signal attenuation is excessive.
− There is no frame structure in the signal from the opposite station.
− The receiver of the board fails.
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SDH Unit
R_LOS
Introduction:
− R_LOS alarm indicates “receive loss of signal”, critical alarm.
− Probable Causes
There is a fiber cut.
− The line attenuation is excessive.
− The receiver of the board fails.
− The transmitter of the opposite station or line transmission fails.
− The XCS cards on the opposite station fails or is offline.
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R_LOF/R_LOS Clearing Procedure:
SDH Unit
Step Action
1Check whether there is any higher-level R_LOS alarm on the T2000. Clear these higher-level alarms first.If the alarm does not clear, continue with the next step.
2Check whether the received optical power of the board reporting the alarm is normal. If yes, turn to Step 9.If not, continue with the next step.
3 Clean the fiber connector and the receiving optical interface of the board. If the alarm does not clear, continue with the next step.
4Check if the connection between local flange and the optical attenuator is correct, and if the attenuation value is too high. If there is a fault, clear it. Then, check if the alarm clears. If the alarm persists, continue with the next step.
5Check if the transmitting optical power of the opposite station is normal. If not, replace the line board. If yes, clean the fiber connector of the opposite station.
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R_LOF/R_LOS Clearing Procedure:
SDH Unit
Step Action
6
If the alarm persists, check if the connection between local flange and the optical attenuator of the opposite station is correct, and if the attenuation value is too high. If there is a fault, clear it. Then, check if the alarm clears. If the alarm persists, continue with the next step.
7Check the fiber. If there is a problem, clear it. Then, check if the alarm clears. If the alarm persists, continue with the next step.
8Replace the line board reporting the alarm at the local station. If the alarm does not clear, continue with the next step.
9Replace the GXCS, EXCS, UXCS, or XCE on the local station. If the alarm does not clear, continue with the next step.
10Replace the line board on the opposite station. If the alarm does not clear, continue with the next step.
11 Replace the GXCS, EXCS, UXCS, or XCE on the opposite station.
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SDH Unit
B2_OVER
Introduction:
− B2_OVER alarm indicates “indication of excessive B2 errors
in the multiplex section”, major alarm.
Probable Causes :
− The received signal attenuation is excessive.
− The fiber end is not clean.
− The fiber connector is connected incorrectly.
− The receiver of the local station fails.
− The transmitter of the opposite station fails.
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SDH Unit
B2_OVER Clearing Procedure
Step Action
1Check whether there are any higher-level alarms, such as R_LOS, R_LOF or B1_EXC on the T2000. Clear these higher-level alarms first.If the alarm does not clear, continue with the next step.
2Check whether the working temperature of the equipment is too high. If yes, lower the temperature.Then, if the alarm persists, continue with the next step.
3Replace the line board reporting the alarm at the local station.If the alarm does not clear, continue with the next step.
4Replace the GXCS, EXCS, UXCS, or XCE on the local station.If the alarm does not clear, continue with the next step.
5Replace the line board on the opposite station.If the alarm does not clear, continue with the next step.
6 Replace the GXCS, EXCS, UXCS, or XCE on the opposite station.
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SDH Unit
MS_AIS
Introduction:
MS_AIS alarm indicates “multiplex section alarm indication”, which is
a major alarm.
Probable Causes
The opposite station transmits the MS_AIS signal.
The GXCS, EXCS, UXCS, or XCE of the opposite station fails.
A fault occurs in the receiver of the board.
:
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SDH Unit
MS_AIS Clearing Procedure
Step Action
1
Check whether the corresponding line board reports R_LOS or R_LOF
alarm on the T2000. If there is a R_LOS or R_LOF, clear it.
Then, check if the alarm clears. If the alarm persists, continue with the
next step.
2Reset or replace the line board on the local station.
If the alarm does not clear, continue with the next step.
3Reset or replace the line board on the opposite station.
If the alarm does not clear, continue with the next step.
4Reset or replace the GXCS, EXCS, UXCS, or XCE on the opposite
station.
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SDH Unit AU_AIS
Introduction:
AU_AIS alarm indicates “AU alarm indication”, which is a major
alarm.
Probable Causes:
The opposite station sends AU_AIS.
The transmitter of the opposite station fails.
The receiver of the local station fails.
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SDH Unit
AU_AIS Clearing ProcedureStep Action
1
Check whether there are any higher-level alarms, such as R_LOS, R_LOF, B1_EXC or
B2_OVER, on the T2000. Clear these higher-level alarms first. If the alarm does not clear,
continue.
2Check whether the NE is under the protection switching. If yes, remove the fault. If the alarm
does not clear, continue.
3Check whether the service configuration of the NE is correct. If not, modify the incorrect
configuration. Then, check whether the alarm clears. If not, continue.
4 Use the alarm analysis and loopback methods to find the NE on which a fault occurs.
5 Replace the line board reporting alarms on the faulty NE. If the alarm does not clear, continue.
6 Replace the XCS board on the faulty NE. If the alarm does not clear, continue.
7 Replace the line board of the opposite station. If the alarm does not clear, continue.
8 Replace the GXCS, EXCS, UXCS, or XCE board on the opposite station.
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SDH Unit
BD_STATUS
Introduction:
BD_STATUS alarm indicates “board offline”, major alarm.
Probable Causes:
The board is not inserted.
The board is not fully inserted.
The mailbox fails.
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SDH Unit
BD_STATUS Clearing Procedure
Step Action
1 Check whether the corresponding board is in the slot.
2 Remove and re-insert the board.
If the alarm does not clear, continue with the next step.
3 Replace the board.
If the alarm does not clear, continue with the next step.
4 Replace the backplane of the local station.
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SDH Unit
Other Alarms
Name Description
MS_RDI Multiplex section remote defect indication, minor alarm.
MS_REI Multiplex section remote error indication, warning
AU_LOP AU loss of pointer, minor alarm.
HP_TIM Higher order path tracking identification mismatch, minor alarm.
HP_SLM Higher order path signal identification mismatch, minor alarm.
HP_RDI Higher order path remote defect indication, minor alarm.
HP_REI Higher order path remote error indication, minor alarm.
HP_UNEQ No loading error in the higher order path, minor alarm.
IN_PWR_ABN Input power abnormal, major alarm.
LASER_SHUT Laser shut down, major alarm.
LOOP_ALM Loop alarm, minor alarm.
COMMUN_FAIL Board serial port communication failure, major alarm.
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Chapter 2 Chapter 2 Alarm& Performance Event ClearingAlarm& Performance Event Clearing
2.1 SDH Unit2.1 SDH Unit
2.2 2.2 PDH UnitPDH Unit
2.3 Ethernet Unit2.3 Ethernet Unit
2.4 Cross-connect and timing Unit2.4 Cross-connect and timing Unit
2.5 SCC Unit2.5 SCC Unit
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PDH Unit
TU_AIS
Introduction:
− TU_AIS alarm indicates “TU alarm indication”, which is a
major alarm.
Probable Causes
− There are errors in configuration data.
− The corresponding path at the opposite station fails.
− There is a higher level alarm.
− The cross-connect board fails.
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PDH Unit
TU_AIS Clearing Procedure
Step Action
1Check whether there are any higher-level alarms, such as R_LOS, R_LOF or HP_SLM, on the T2000. Clear these higher-level alarms first.
If the alarm does not clear, continue with the next step.
2Check whether the NE is in the protection switching state. If yes, remove the fault causing the switching.
Then, check whether the alarm clears. If not, continue with the next step.
3Check whether the service configuration of the NE is correct. If not, modify the incorrect configuration.
Then, check whether the alarm clears. If not, continue with Step 4.
4Replace the alarm reporting tributary board.
If the alarm does not clear, continue with the next step.
5 Replace the GXCS, EXCS, UXCS, or XCE.
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PDH Unit
TU_LOP
Introduction:
− TU_LOP alarm indicates “TU Loss of Pointer”, which is a
major alarm.
Probable Causes:
− The interface between the tributary board and the cross-
connect board fails.
− There are errors in configuration data.
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PDH Unit
TU_LOP Clearing Procedure
Step Action
1
Check whether there are any higher-level alarms, such as R_LOS, R_LOF or HP_SLM, on the
T2000. Clear these higher-level alarms first.
If the alarm does not clear, continue with the next step.
2
Check whether the NE is in the protection switching state. If yes, remove the fault causing the
switching.
Then, check whether the alarm clears. If not, continue with the next step.
3Check whether the service configuration of the NE is correct. If not, modify the incorrect
configuration.
4If the alarm persists, replace the alarm reporting tributary board and then view whether the
alarm is removed.
5 If the alarm persists, replace the GXCS, EXCS, UXCS, or XCE.
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PDH Unit
T_ALOS
Introduction:
− T_ALOS alarm indicates “E1 interface loss of analog signal”,
which is a major alarm.
Probable Causes:
− No E1 service is accessed.
− The output port of the E1 interface on the DDF side is
disconnected or loosened.
− The input port of the E1 interface at the local station is
disconnected or loosened.
− Board failure.
− Cable fails.
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PDH Unit
T_ALOS Clearing Procedure
Step Action
1Check whether the corresponding path of the tributary board reports the TU_AIS or TU_LOP alarm on the T2000. If yes, clear the alarm.
Then, check if the T_ALOS clears. If not, continue with the next step.
2Perform self-loop (hardware inloop) for the path reporting the alarm at the DDF. If the alarm clears, the fault lies in the equipment of the opposite end. Remove the fault.
Then, check if the alarm clears. If not, continue with the next step.
3Perform self-loop (hardware inloop) for the path at the interface board. If the alarm clears, the fault lies in the signal cable connection. Remove the fault.
Then, check if the alarm clears. If not, continue with the next step.
4Perform inloop for the path on the T2000. If the alarm clears, the fault lies in the interface board. Remove and then re-insert or replace the interface board.
Then, check if the alarm clears. If not, continue with the next step.
5 Replace the service processing board.
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PDH Unit
Other Alarms
Name Description
LP_RDI Lower order path remote defect indication, minor alarm.
LP_REI Lower order path remote error indication, minor alarm.
NO_BD_SOFT No board software, critical alarm.
PS Protection switching is initiated, major alarm.
UP_E1_AIS 2M signal alarm indication, minor alarm.
DOWN_E1_AIS E1 down signal alarm, minor alarm.
ALM_SUBCARD_ABN Find the fault of sub-board, major alarm.
BD_STATUS Board offline, major alarm.
COMMUN_FAIL Serial port communication failure, major alarm.
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Chapter 2 Chapter 2 Alarm& Performance Event ClearingAlarm& Performance Event Clearing
2.1 SDH Unit2.1 SDH Unit
2.2 2.2 PDH UnitPDH Unit
2.3 Ethernet Unit2.3 Ethernet Unit
2.4 Cross-connect and timing Unit2.4 Cross-connect and timing Unit
2.5 SCC Unit2.5 SCC Unit
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Ethernet Unit
ALM_SUBCARD_ABN
Introduction:
− ALM_SUBCARD_ABN alarm indicates “find the fault of sub-board”,
which is a major alarm.
Probable Causes:
− The interface board does not match the processing board.
− Clearing Procedure:
Step Action
1 Check whether the interface board is inserted correctly. If not, re-insert the board.
2If the alarm persists, check the configuration of the corresponding service
processing board on the T2000. Modify the incorrect configuration.
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Ethernet Unit
Other AlarmsName Description
AU_AIS AU alarm indication, major alarm.
ETH_LOS Ethernet Receive loss of input signal, critical alarm.
PROTOCOL_MM Encapsulation protocol types mismatched, critical alarm.
NO_BD_SOFT No board software, critical alarm.
BD_STATUS Board not in position alarm, major alarm.
COMMUN_FAIL Serial port communication failure, major alarm.
LOOP_ALM Loop alarm, minor alarm.
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Chapter 1 Chapter 1 Alarm& Performance Event ClearingAlarm& Performance Event Clearing
2.1 SDH Unit2.1 SDH Unit
2.2 2.2 PDH UnitPDH Unit
2.3 Ethernet Unit2.3 Ethernet Unit
2.4 Cross-connect and timing Unit2.4 Cross-connect and timing Unit
2.5 SCC Unit2.5 SCC Unit
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Cross-connect and timing Unit
APS_FAIL
Introduction:
− APS_FAIL alarm indicates “APS protection switching failed”,
which is a major alarm.
Probable Causes:
The multiplex section protection (MSP) parameters of the nodes
are incorrect.
The MSP parameters of the nodes are lost.
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Cross-connect and timing Unit
Clearing Procedure
Step Action
1
Check whether the MSP parameters of the nodes are correct. If not, modify the
incorrect parameters.
If the alarm does not clear, continue with the next step.
2Check whether the MSP protocol is normal. If not, stop and then restart the
protocol.
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Cross-connect and timing Unit
APS_INDI
Introduction:
− APS_INDI alarm indicates “APS protection switching
indication”, which is a major alarm.
Probable Causes:
− MSP switching is initiated.
− Clearing Procedure
Step Action
1For an MSP ring, this alarm indicates that MSP switching is initiated. Remove the
fault.
2
For a non-ring MSP network, this alarm indicates that the APS protocol is initiated
abnormally. Check whether the MSP parameters of the nodes are correct. If not,
modify the incorrect parameters.
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Cross-connect and timing Unit
EXT_SYNC_LOS
Introduction:
− The EXT_SYNC_LOS alarm indicates “loss of external synchronous source”, which is a minor alarm.
− The external clock source is lost.
Probable Causes:
− Clearing Procedure:
Step Action
1 Check whether the equipment that provides the external clock works efficiently.
2Check whether the external clock cable is connected correctly and whether the
connectors are in good contact. If there is a fault, remove it.
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Cross-connect and timing Unit
LTI
Introduction:
− LTI alarm indicates “loss of synchronization source”, which is a major alarm.
Probable Causes:
Non S1 mode:
− There is a fiber cut (the line clock is traced).
− No external clock source is input (the external clock is traced).
− The synchronization source is set as non-retrieve, is blocked or is set incorrectly.
S1 mode:
− There is a fiber cut.
− The free-run mode is in active.
− The synchronization source is set incorrectly.
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Cross-connect and timing Unit
Clearing Procedure:
Step Action
1View the clock source traced by the NE. Clock source could be external clock source, line clock source, and tributary clock source.
External clock source
2Check whether the output signal of the external clock device is normal. If not, replace the device.Then, check if the alarm clears. If the alarm persists, continue with the next step.
3Check whether the external clock input mode is proper (2 MHz or 2 Mbit/s). If the mode mismatches each other, correct the setting.Then, check if the alarm clears. If the alarm persists, continue with the next step.
4Check whether the external clock input impedance is proper ( 75-ohm or 120-ohm). If the impedance mismatches each other, correct the setting.Then, check if the alarm clears. If the alarm persists, continue with the next step.
5Check whether the clock input cable is connected correctly. If not, connect the cable correctly. Then, check if the alarm clears. If the alarm persists, continue with the next step.
6 Reset or replace the GXCS, EXCS, UXCS, or XCE.
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Cross-connect and timing Unit
Clearing Procedure:
Step Action
Line clock source
7
Check whether the corresponding line board reports R_LOS alarm through the T2000. If there
is a R_LOS alarm, clear it.
Then, check if the alarm clears. If the alarm persists, continue with the next step.
8
Reset or replace the line board.
If the alarm does not clear, continue with the next step.
9 Reset or replace the GXCS, EXCS, UXCS, or XCE.
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Cross-connect and timing Unit
Other Alarms
Name Description
BUS_ERR Bus error, major alarm.
CLK_NO_TRACE_MODE Clock entering into non-tracing running mode, minor alarm.
S1_SYN_CHANGE Clock reference source change in S1_Mode, minor alarm.
SYN_BAD Synchronization source deteriorated, minor alarm.
SYNC_C_LOS Synchronization source level loss, warning.
NO_BD_SOFT No board software, critical alarm.
COMMUN_FAIL Serial port communication failure, major alarm.
BD_STATUS Board not in position alarm, major alarm.
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Chapter 2 Chapter 2 Alarm& Performance Event ClearingAlarm& Performance Event Clearing
2.1 SDH Unit2.1 SDH Unit
2.2 2.2 PDH UnitPDH Unit
2.3 Ethernet Unit2.3 Ethernet Unit
2.4 Cross-connect and timing Unit2.4 Cross-connect and timing Unit
2.5 SCC Unit2.5 SCC Unit
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SCC Unit
NESTATE_INSTALL
Introduction:
− NESTATE_INSTALL alarm indicates “NE in install state”,
which is a critical alarm.
Probable Causes:
− The NE is under installation.
− Clearing Procedure:
Step Action
1 Correct the configuration data and re-send the data.
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SCC Unit
WRG_BD_TYPE
Introduction:
− WRG_BD_TYPE alarm indicates “wrong inserted board
type”, which is a minor alarm.
Probable Causes:
− A wrong board is inserted.
− There are errors in the board configuration.
− Clearing ProcedureStep Action
1 Check whether the board is of the right type. If not, insert a right one.
2If the alarm persists, check whether the board configuration is correct. If not, modify
the incorrect configuration.
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SCC Unit
Other Alarms
Name Description
HARD_BAD The HARD_BAD alarm indicates “hardware fails”, critical alarm.
NESF_LOST Lost of one nesoft, critical alarm.
NODEID_MM Multiplex section node ID mismatch, Major alarm.
POWER_ABNORMAL Power is abnormal, major alarm
POWER_FAIL Power failure, major alarm
COMMUN_FAIL Serial port communication failure, major alarm.
BD_STATUS Board not in position alarm, major alarm.
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NE2
NE4
NE3 NE1 NE5SNCP
E
E
E
E
W
W
W
W
W2 W
Case of 2 fiber SNCP ring with no protection chain. NE1, NE2, NE4, NE5 is OSN 3500 equipment, NE3 is OSN 2500 REG.
NE5 NE1 NE2 NE4
T1 : 1-16 T1 : 1-16
T2 : 1-16 T1 : 1-16
T2 : 1-16 T2 : 1-16
T1 : 1-15 T3 : 1-15
All of the traffic are unidirectional
1#-16#VC12
17#-32# VC12
33#-48#VC12
49#-63# VC12
Exercise
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Exercise
PQ1 (NE1)
W
E
NE5NE4NE3NE2NE1Card\NE
- MS_RDI - - -
- - R_LOS MS_AIS -
- - - -
If the Tx fiber between NE2 and NE3 is broken, please fill in the blank. If no alarm please fill in with “-” .
A. R_LOS; B. MS_AIS; C. MS_RDI; D. TU_AIS; E. LP_RDI;
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Generation of Alarm& Performance
Alarm& Performance Event Clearing
Case of Ring with Chain
Summary