sdh/sonet alarms & performance monitoring
DESCRIPTION
SDH/SONET alarms & performance monitoringTRANSCRIPT
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SDH/SONET ALARMS & PERFORMANCE MONITORING
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• Standards• Alarms Introductions and Examples• Performance Monitoring Parameters• FAQs
2
Contents
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Bell Communications Research (Bellcore, BCR)prepares equipment standards for North American community
ANSI Committee T1 prepares telecommunications standards (rates and formats) creator of SONETANSI (American National Standards Institute) accreditedsponsored by ATIS (Alliance for Telecommunications Industry Solutions)
ITU-T G.826,G.783
3
Standards
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Alarms Introductions and Examples
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Alarm Overview
Œ
�
Ž
��
V1
V2
V5 ‘’
1. RS2. MS3. HP4. AU5. TU6. LP7. PPI
SDH Frame
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A1 A1 A1 A2 A2 A2 J0
B1 E1 F1
D1 D2 D3
H1 H1 H1 H2 H2 H2 H3 H3 H3
B2 B2 B2 K1 K2
D4 D5 D6
D7 D8 D9
D10 D11 D12
S1 Z1 Z1 Z2 Z2 M1 E2
RSOH
MSOH
AUPointe
r
J1
B3
C2
G1
F2
H4
F3
K3
N1
VC-4 POH
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The SDH Frame
VC-11 VC-12 VC-2
V5 V5 V5
25 34 106
N2 N2 N2
25 34 106
K4 K4 K4
25 34 106
Lower order VC-n
POH
Number of bytes of data
separating fields.
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A1, A2 RS-LOF Provides a frame alignment pattern [A1 =11110110, A2 = 00101000]. The frame alignment word of an STM-n frame is 3 X n A1 bytes followed by 3 X n A2 bytes.
J0 RS-TIM Regenerator section trace. [16 byte frame including CRC7 (1st byte.) Supports continuity testing between transmitting and receiving device on each regenerator section.
Z0 Spare. Reserved for future international standardisation.
B1 RS-EXC RS-DEG
Provides regenerator section monitoring. The regenerator section BIP-8 provides end-to-end error performance monitoring across an individual regenerator section and is calculated over all bits of the previous STM-n frame after scrambling. Computed value is placed in B1 byte before scrambling
E1 Provides local orderwire channel for voice communications between regenerators, hubs and remote terminal locations.
F1 Allocated to user’s purpose [e.g. temporary data/voice channel connection for special maintenance applications]
D1-D3 COMMS 192 kb/s message based data communications channel providing administration, monitor, alarm and maintenance functions between regenerator section termination equipment
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RSOH [Regenerator Section Overhead]
SDH FrameB1 – Is not supported in OM4000 NE’s due to redundancy and this NE is primarily used as an ADM
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B2 MS-EXC MS-DEG
Provides multiplex section error monitoring. The BIP-n X 24, of an STM-n frame, provides end-to-end error performance monitoring across an individual multiplex section and is calculated over all bits of the previous STM-n frame except for the first three rows of SOH. Computed value is placed in B2 byte before scrambling.
K1, K2 MS-AIS MS-RDI
Two bytes allocated for APS signalling for multiplex section protection.
K2 [b6-b8] contains MS-RDI and MS-AIS status information.
D4-D12
COMMS Provides 576 kb/s data communication channel between multiplex section termination equipment. Used to carry network administration and maintenance information.
S1 Synchronisation status messages. S1 [b5-b8] indicates which of the four levels of synchronisation is being used at the transmit end of a multiplex section.
M1 MS-REI Multiplex section remote error indication [MS-REI]. Conveys the number of B2 errors detected by downstream equipment.
E2 Provides express orderwire channel for voice communications between multiplex section terminating equipment
H1-H3 AU-AIS TU-AIS [TU-3] AU-LOP TU-LOP [TU-3]
AU pointer bytes are associated with, but not part of, the MSOH. The pointer contained in H1 and H2 points to the location where the VC-n begins. The last ten bits [b7-b16] of H1, H2 carry the pointer value [0 to 782]. The H3 bytes are ‘pointer action’ bytes and carry ‘live’ information from a VC4, during the STM-n frame in which negative pointer adjustment occurs
8
MSOH [Multiplex Section Overhead]
SDH FrameMSP Protocol Bytes K1 [b1-4] – type of request [b5-8] – channel number K2 [b1-4] – channel bridging [b5] – protection architecture
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HO-POH [Higher order path Overhead]
J1 HP-TIM [VC-4] LP-TIM [VC-3]
The first byte in the virtual container. Its location is indicated by the AU pointer [H1,H2 bytes]. Provides a higher order trail trace identifier [64-byte free format string or 16-byte frame including CRC7. Supports end-to-end monitoring of a higher order path.
B3 HP-EXC HP-DEG LP-EXC+DEG [VC-3]
Provides higher order path error monitoring. The BIP-8 is calculated over all bits of previous VC-n. Computed value is placed in B3 byte before scrambling.
C2 HP-AIS LP-AIS [VC-3] HP-UNEQ+PLM LP-UNEQ+PLM [VC-3]
High order signal label. Indicates composition or the maintenance status of the associated container.
G1 HP-REI + RDI LP-REI + RDI [VC-3]
Higher order path status. Send status and performance monitoring information from receiving path terminating equipment to originating equipment. Allows status and performance of two-way path to be monitored at either end. G1 REI [b1-b4] RDI [b5]
F2 Higher order path user channel. Allocated for network operator communications between path terminations.
H4 HP-LOM Position indicator. Multiframe phase indication for TU structured payloads. H4 [b7-b8]
F3 Higher order path user channel. Allocated for network operator communications between path terminations
K3 Higher order path automatic protection switching [b1-b4]. The rest of the bits [b5-b8] are allocated for future use.
N1 Higher order tandem connection monitoring. There are two possible implementations described in Annex C and Annex D of ITU-T G.707. In Annex C, the N1 byte provides a tandem connection incoming error count [IEC] and the remaining four bits provide an end-to-end data link
SDH Frame
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V5 [VC-12] LP-AIS [b5-b7] LP-REI [b3] LP-RDI [b8] LP-EXC [b1-b2] LP-UNEQ [b5-b7] LP-PLM [b5-b7]
Provides BIP-2 error checking, signal label and path status information.
J2 LP-TIM [VC-12] Lower order trail trace identifier [16 byte frame including CRC7]. Supports end-to-end monitoring of a lower order path
N2 Lower order tandem connection monitoring. Contains BIP-2 error checking, AIS, tandem connection REI [TC-REI], outgoing error indication [OEI] and a 76-byte multiframe containing a tandem connection access point identifier [TC-APid].
K4 Lower order path automatic protection switching [b1-b4] and enhanced remote defect indication [b5-b7].
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LO-POH [Lower order path Overhead]
SDH Frame
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Anomalies, defects and alarms
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Alarm A human observable indication that draws attention to a failure usually giving an
indication of the severity of the fail The report to the user of a defect
Anomaly The smallest discrepancy which can be observed between the actual and desired
characteristics of an item. The occurrence of a single anomaly does not constitute an interruption in the ability to perform a required function. Anomalies are used as the input for the Performance Monitoring [PM] process and for the detection of defects A single occurrence of, or commencement of a pre-defined condition
Defect The density of anomalies has reached a level where the ability to perform a
required function has been interrupted. Defects are used as input for PM, the control of consequent actions, and the determination of faults cause The persistent or repeated occurrence of an anomaly for a pre-defined
duration or number of repetitions
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Defect naming
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The origin of defect naming can be confusing. The following points should help when dealing with the nomenclature
Defects derived from path overheads begin: LP, HP, LPOM or HPOM. Defects derived from section overheads begin: RS or MS. Defects related to conditions affecting a whole VC and its pointer begin: AU or TU. AU is used
for VC-4s. TU is used for TU-3s, TU-2s and TU-12s. Defect types beginning TU are not distinguishable.
When distinguishing LP and LPOM remember that LPs will be present when traffic is terminated and LPOMs when traffic is un-terminated.
A defect type (e.g. LP-EXC) has two parts: Part 1 is a "function point“ Part 2 is an "alarm category".
Example: LP-EXC. This defect is detected at the LP function point - the "low order path termination" function point. The category of the defect is "EXC" - EXCessive bit errors.
Excessive bit errors in a VC-3 will give an LP-EXC defect, as will excessive bit errors in a VC-12. The two defects share their type but they have distinct instances. When the corresponding alarm is reported to the user the type and instance will be reported.
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Defect Correlation
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If a defect is subject to correlation it will NOT be raised if another alarm is present.
Aim of defect correlation The aim of correlation is to present to the operator only the alarm closest to the
source cause of a set of related defects. This reduces the amount of fault analysis required of the operator and the traffic on communication channels.
Example: If EXC is present it will hide the presentation of TIM, PLM, UNEQ etc. More specifically EXC will ‘mask’ TIM, PLM and UNEQ alarms.
A masks B
HP-EXC
HP-TIM HP-PLM HP-UNEQ
A
B
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Card Fail
Card Fault
Wrong Card
Unexpected Card
Alarm raised on the card/slot instance
A
B
= ‘A masks B’
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Plug In Unit Defect Correlation
• Plug In Unit [PIU] related defects– For a given instance of PIU in a slot
– All defects present within that PIU will be masked
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PPI LOS
A
B
= ‘A masks B’
PPI UNEXP SGNL
PPI EXC
PPI DEG PPI AIS INT LP IP BUFFER
INT HP IP BUFFER
PPI LOF
PPI LOM
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PDH Traffic Defect Correlation
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AU AIS
AU LOPMS DEG
MS EXC
MS AIS
RS TIMQECC COMMS FAIL
RS LOF
ES CMI
RS LOS RS UNEXPECTED SIGNAL
MS RDI
MS RDI
HPOM EXC
HPOM TIM
HPOM PLM
HPOM UNEQ
= ‘A masks B’
A
B
= ‘A masks B, dependent on AIS consequent action configuration of A’
A
B
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SDH traffic DEFECT correlation
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HP EXC
INT HP OP BUFF
HP DEG HP LOM
TU LOP
HP TIM HP PLM HP UNEQ
HP RDI
HP REIPPI LOF
TU AIS
INT TU LOP
INT TU AIS
LP EXC
LPOM EXC
LPOM TIM LPOM PLM
LPOM UNEQ
LP TIM LP PLM
LP UNEQ
LP RDI
LP REI
LP DEG
INT LP OP BUFFER
= "A masks B if B's TU type is
TU-12"
A
B
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What is a path?
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A path is an end to end circuit The ends of a LO path are where traffic is brought into SDH or removed from SDH Paths carry VCs LO VCs are
generated where traffic is brought into SDH and terminated where it is removed
HO VCs are Generated / terminated where traffic is brought into SDH or when LO VCs are brought
into / removed from a HO VC
Low Order Path
Multiplexer
Regenerator
High Order Path
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Carrying a 2 Meg circuit in a STM frame
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2M example whereHigh order paths are
encased in STM frames when they pass between nodesLow order paths are
threaded through high order paths
2M PDHLO pathHO pathMSRS
Multiplexor Regenerator
STM-1 tributary with a LO connection
2M trib
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SONET Layers
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DS1
DS3
DS1
STS Path
Line
Section
Photonic
VT Path
DS3
Section SectionSectionSection
Line LineLine
STS Path STS Path
VT Path
PathTerminatingEquipment
(PTE)
SectionTerminatingEquipment
(STE)
LineTerminatingEquipment
(LTE)
PathTerminatingEquipment
(PTE)
PathTerminatingEquipment
(PTE)
STS Path
Line
Section
Photonic
Section
Photonic
STS Path
Line
Section
Photonic
VT Path
Line
Section
Photonic
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There are four sections – Regenerator Section (RS), Multiplex Section (MS), Higher
Order Path Section (HP), and Lower Order Path Section (LP)
RS is a part (section) of the optical fibre network, within which RSOH part of SDH frame is NOT opened
MS is a part (section) of the optical fibre network, within which MSOH part of SDH frame is NOT opened
HP is a part (section) of the optical fibre network, within which higher order VC part of SDH frame is NOT opened (it may be opened only for interpreting HOPOH)
LP is a part (section) of the optical fibre network, within which lower order VC part of SDH frame is NOT opened (it may be opened only for interpreting LOPOH)
SDH Section Hierarchy
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SDHInterface cross-connect
unit
SDHInterface
PDH interface
High order part
Downlink signal flow
Downlink signal flow & High order part
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SDHInterface cross-connect
unit
SDHInterface
PDH interface
Low order part
Uplink signal flow & Low order part
Uplink signal flow
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AIS (Alarm Indication Signal)
Two Common Alarms
Inserts the all “1”s signal into the Low level circuits, Indicating that the signal is
unavailable. Common AIS alarms include MS_AIS, AU_AIS, TU_AIS and E1_AIS.
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.
RDI (Remote Defect Indication)
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Alarms & Performance of High Order Part
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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 Unit
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Alarms & Performance of High Order Part
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Diagram of Alarm Generation
Frame synchronizer& RS overhead processor
(RST)
MS overhead processor
(MST)
Pointer processor& HP overhead processor
(MSA, HPT)
LOS
LOF
B1 Err
A1,A2
B1
AIS
MS_AIS
B2 Err
K2
B2
MS_REIM1
MS_RDIK2
“1” AIS
AU_AIS
AU_LOPH1,H2
H4B3 Err
J1
HP_SLMC2
“1”
HP_LOM
HP_TIM
HP_UNEQ
HP_REI
HP_RDI
H1,H2
C2
B3
G1
G1
“1” XCS
STM-N
Optical
Signal
Downlink signal flow Alarm report or return
Signal transfer point (Insert down all "1"s signal)
Alarm termination point (Report to SCC unit)
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Alarms & Performance of High Order Part
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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
Downlink Signal Flow
Frame synchronizer and RS overhead processor
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Alarms & Performance of High Order Part
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Downlink 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-8 computing to check bit error (B2_SD and B2_OVER)
M1 bytes (MS_REI)
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Alarms & Performance of High Order Part
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Downlink 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 High 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)
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Alarms & Performance of High Order Part
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Uplink Signal Flow
Pointer processor and HP overhead processor
Generates N High 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
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Alarms & Performance of High Order Part
31
Uplink Signal Flow
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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Alarms & Performance of High Order Part
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Uplink Signal Flow
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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Alarms & Performance of Low Order Part
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PDH Interface to Cross-connect Unit
G H I J K
PDH InterfaceCross-connect Unit
HPAHPA LPTLPT LPALPA PPIPPI
Uplink signal Flow
Downlink signal Flow
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Alarms & Performance of Low Order Part
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Diagram of Alarm Generation
PDH Physical InterfaceLow Order Path Adaptation
High Order Path Adaptation& Low Order Path
Termination
E1 Interfac
e
E1 Interfac
e
(PPI)(LPA)(HPA, LPT)
LP_TFIFO
All “1”
LP_SLM
LP_UNEQ
V1,V2
H4
BIP 2
J2
TU_AIS
V5
HP_LOM
LP_TIM
TU_LOP
LP_REI
LP_RDI
V5
V5
XCS
V5
V1,V2
LP_RFIFO
E1_AISAll “1” T_ALOS
E1_AISXCS
Downlink signal flow Alarm report or return
Signal transfer point (Insert down all "1"s signal)
Alarm termination point (Report to SCC unit)
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Alarms & Performance of Low Order Part
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Downlink Signal Flow
High Order Path Adaptation& Low Order Path Termination
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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Alarms & Performance of Low Order Part
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Downlink Signal Flow
Low Order Path Adaptation& PDH Physical Interface
Low 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
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Alarms & Performance of Low Order Part
37
Uplink Signal Flow
Low Order Path Adaptation& PDH Physical Interface Low 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
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Alarms & Performance of Low Order Part
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Uplink Signal Flow
High Order Path Adaptation& Low Order Path
Low 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)
High Order Path Adaptation Adapt VC-12 into TU-12
Map TU-12 into High order VC-4
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Suppression Correlation between SDH Alarms
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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
A B A suppress B
J0_MM MS_AIS B1_EXEC B2_EXEC
A1, A2 Bytes
RSOH, MSOH
(Except A1,A2)
Suppression Relationship
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More on Alarms
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Alarm Understanding Rules
Rule 1
Rule 2
FC 1Alarm reported
Alarm reportedFC 1
ADM 1 ADM 2
ex. a
ADM 1 ADM 2
ex. b
Alarms reported are alarms received
Alarms are reported on SDH Objects41
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Alarm Understanding Rules (…contd.)
Rule 3
ADM 1 ADM 2
ex.
3a. No Object => No Alarms reported
FC on TU12 (1-1-1)
NO TU12
(1-1-1)
3b. Object Mismatch => No Alarms reported
FC on TU12 (1-1-1)
TU11
(1-1-1)
ADM 1 ADM 2
ex.
Note:
These two examples are not possible for AU objectWHY?
See slide 9
NO Alarm reported for FC on TU12 (1-1-1)
NO Alarm reported for FC on TU12 (1-1-1)42
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Alarm Understanding Rules (…contd.)
Rule 4
4a. No PT XC => No Alarms pass-through
FC on AU4 (1)
NO VC4
PT (1)
Alarm reported for FC on AU4 (1)
FC on TU12 (1-1-1)
ADM 1 ADM 2 ADM 3
ex. a
ADM 1 ADM 2 ADM 3
ex. b
NO Alarm pass-through
NO VC12
PT (1-1-1)
NO Alarm pass-through
NO Alarm reported for FC on TU12 (1-1-1)43
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Alarm Understanding Rules (…contd.)
4b. Bigger PT XC => No Alarms reported & Alarm pass-through
FC on TU12 (1-1-1)
Alarm pass-through for
FC on TU12 (1-1-1)
NO Alarm reported
for FC on TU3 (1)
VC4
ADM 1 ADM 2 ADM 3
ex. a
STM-1
links
4c. Smaller PT XC => No Alarms reported (always ??) & Alarm pass-through but on smaller object
FC on TU3 (1)
VC12
(1-1-1)
NO Alarm reported
for FC on TU12 (1-1-1)
ADM 1 ADM 2 ADM 3
ex. b
STM-1
links
Alarm pass-through for
FC on TU12 (1-1-1)
What if Same size PT XC ?
44
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Guide Lines
Alarms reported are alarms received
Object---- No Object
---- Object Mismatch
Privilege of the NE
Upstream / Downstream
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RS Alarms
RS alarms are those, which can be reported even by a pure Regenerator
(who has privilege of opening (interpreting & rewriting) only RSOH)
LOS (Loss of Signal)based on whole RSOH
LOF (Loss of Frame)based on A1, A2 bytes
TIM (Trace Identifier Mismatch)based on J0 byte
SF (Signal Fail)based on B1 byte
SD (Signal Degrade)based on B1 byte
D3D2D1
F1E1B1
J0A2A1
RSOH bytes
Note: The order in which the alarms are written is important,
as we will see later while discussing Alarm masking
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Description of Alarms
LOS
Received power is less than Laser receiver sensitivity (All bits interpreted as ‘0’)
ADM 1 ADM 2
ex. TxRx
RxTx
LOS
Tx off / misconnectivity
Rx off / misconnectivityFiber Cut
Received power is less than Laser receiver sensitivity
(Low power transmitted, Span is longer than specified, Fiber gets deformed etc. etc.)
LOF
Anything other than “F6 28 (Hex)” in any (?) of the A1 A2 bytes (within a STM frame)
-- for consecutive 5 frames (625 µs) OOF (Out of Frame) clearing 2 frames -- for consecutive 24 frames (3 ms) LOF clearing 24 frames
Note: Prolonged LOS => LOF, but not always LOF => LOS
(this fact will be used as one of the Alarm Masking logic later)
LOS clears when 2 consecutive framing patterns are received & no new LOS condition is detected
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Description of Alarms (…contd.)
TIM (J0)
Received J0 trace (1/16 byte(s)) != Expected J0 trace (1/16 byte(s))
Note: For both SF & SD, alarm clearing threshold is 1 decade lower than generation threshold, e.g., Gen. Thr. is 1 in 1000 or higher => Clg. Thr. is 1 in 10000 or lower
SF (B1/B2/B3/V5)
Equivalent BER exceeds alarm generation threshold ( 1 in 10 / 1 in 10 / 1 in 10 )
3 4 5
5 9SD (B1/B2/B3/V5)
Equivalent BER exceeds alarm generation threshold ( 1 in 10 to 1 in 10 )
P1
P2
A B C
Rx trace = C to B
Rx trace = A to B
Tx trace = A to B
Exp trace = A to B
Tx trace = C to B
Exp trace = C to B
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MS Alarms
MS alarms are those, which can be reported by a Add-Drop Multiplexer, irrespective of cross-connect configuration
(who has privilege of opening (interpreting & rewriting) RSOH, MSOH, AU pointers plus opening HOPOH(s) / TU Pointers / LOPOH(s) depending upon cross-connect configuration)
AIS (Alarm Indication Signal) reported based on K2 byte -- bits 6,7,8
SF (Signal Fail)based on B2 bytes
SD (Signal Degrade)based on B2 bytes
RDI (Remote Defect Indication)based on K2 byte -- bits 6,7,8
MSOH bytes
K2K1B2
D6D5D4
D9D8D7
E2M1S1
D12D11D10
Note 1: The order in which the alarms are written is important, we will see later while discussing Alarm masking
Note 2: MS-AIS is also called Line-AIS or AIS on STM port
MS-RDI is also called Line-RDI or RDI on STM port49
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Description of Alarms (…contd.)
Example of generation of AIS, RDI
ADM
Any traffic affecting RS Alarm or MS-AIS (Rx)
MS-AIS (Gen)
MS-RDI
Any traffic affecting HP Alarm or AU-AIS (Rx)
AU-AIS (Gen)
HP-RDI
Any traffic affecting LP Alarm or TU-AIS (Rx)
TU-AIS (Gen)
LP-RDI
Example of reception of TU-AIS, LP-RDI
ADM 1 ADM 2 ADM 3
E1
E1
VC12
VC12
VC12
TU-AIS (Rx)
LP-RDI (Rx)
Any traffic affecting RS/HP/LP Alarm
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HP / LP Alarms
HP / LP alarms are those, which can be reported by a Add-Drop Multiplexer, having HO / HO & LO object (LO object => LO cross-connect)
(who has privilege of “opening (interpreting & rewriting) RSOH, MSOH, AU Pointers plus at least interpreting HOPOH(s)” / “opening (interpreting & rewriting) RSOH, MSOH, AU Pointers, HOPOH(s), TU Pointers plus at least interpreting LOPOH(s)” depending upon cross-connect configuration)
HP-AIS reported based on H1, H2 bytes
HP-LOP (Loss of Pointer) based on H1, H2 bytes
HP-UNEQ (unequipped) based on C2 byte
HP-TIM based on J1 byte
HP-SF based on B3 byte
HP-SD based on B3 byte
HP-RDI based on G1 byte -- bit 5
Note 1: Same as before
Note 2: HP-Alarm is also
called AU-Alarm
or Alarm on AU
LP-Alarm is also
called TU-Alarm
or Alarm on TU
K3F3
H4
F2
G1
C2
B3
J1
N1
HOPOH
bytes
H1, H2, H3 – AU Pointer bytes
51
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HP / LP Alarms (…contd.)
LP-AIS reported based on V1, V2 bytes
LP-LOP based on V1, V2 bytes
LOM (Loss of Multiframe) based on H4 byte – bits 7,8
HP-PLM / SLM (Payload / Signal Label Mismatch)based on C2 byte
LP-UNEQ based on V5 byte – bits 5,6,7
LP-TIM based on J2 byte
LP-SF based on V5 byte – bits 1,2
LP-SD based on V5 byte – bits 1,2
LP-RDI based on V5 byte -- bit 8
LP-PLM / SLM based on V5 byte – bits 5,6,7
Note 1: Same as before
Note 2: Whole of this slide assumes
TU2/TU12/TU11 for LP. If there
is TU3 with AU4 mapping, then
also it is LP but Pointers & POH
bytes will be like HO
K4
N2
J2
V5
LOPOH bytes
V1, V2, V3 – TU Pointer bytes
52
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SONET/SDN Terminology Translation
53
SDHVC-11 (virtual container)VC-12VC-2VC-3VC-4
TU-11 (tributary unit)TU-12TU-2TU-3
TUG-2 (TU group)TUG-3
AU-3 = VC-3 + PtrAU-4 = VC-4 + Ptr
AUG = 1 x AU-4,or 3 x AU-3s
STM-1 = AUG + SOH
STM-N = N AUGs + SOH
Regenerator Section
Multiplex Section
SONETVT-1.5 SPEVT-2 SPEVT-6 SPESTS-1 SPESTS-3c SPE
VT-1.5 (Virtual Tributary size 1.5)VT-2VT-6 no SONET equivalent (like a 50 Mbit/s VT)
VT GroupNo SONET equivalent
STS-1 SPE + STS-1 PointerSTS-3c SPE + STS-3c Pointer
logical entity (not defined)
STS-3
STS-3N
Section Layer
Line Layer
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Alarm Propagation Examples
For every example,
Assumption(s) is/are stated
Root Cause(s) is/are stated
Diagrammatic representation is made (OFCs are shown in cyan) Alarm(s) generated / condition(s) generated for reporting alarms is/are
shown in black Alarm(s) existing at a port is/are shown in red
Alarm(s) masked at a port is/are covered with Alarm(s) reported at secondary supprressed alarm page is/are shown
in pink, italicised Note(s), whenever required is/are mentioned in green54
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Alarm Propagation Examples (…contd.)
Example 1
A B
Assumption: AU-4 Mapping on both ports Root Cause: NO XConnect on both ports
AU4 Signal Label Unequipped
HP-RDI
HP- UNEQ
HP-RDI
AU4 Signal Label Unequipped
HP- UNEQ
HP-RDI
HP-RDI
Note: 1) if AU-3 mapping, then what happens?
2) In newer version of Tejas software, UNEQ is not reported for this root cause
55
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Alarm Propagation Examples (…contd.)
HP-RDI
HP- UNEQ
AU4 Signal Label Unequipped
Signal Label TUG-structure
HP-SLM
HP-RDI
TU-LOP
Example 2
Assumption: AU-4 Mapping on both ports, Root Cause: NO XConnect on the port of B
A B
E1
VC12
Invalid TU Pointer value
LP-RDI
Note: LP-RDI is not reported on B (See Rule 3a)
HP-SLM default action is “report SLM, no downstream AIS”
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LOS
MS-AIS
AU-AIS
TU-AIS
MS-RDI
HP-RDI
LP-RDI
Alarm Propagation Examples (…contd.)
VC-12 VC-12
E1 E1
A CB (Reg.
)
Example 3
Assumption: AU-4 Mapping on both ports of A & C
Root Cause: Fiber cut in the link from A to B
AIS
MS-RDI
HP-RDI
LP-RDINote: The Reg. can not generate any RDI
Actually at C, AU-AIS & TU-AIS conditions are also received57
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LOS
MS-RDI
HP-RDI
LP RDI
Alarm Propagation Examples (…contd.)
MS-AIS
LP RDI MS-RDI
HP-RDI
E1 E1
VC-12 VC-12
A CB
Example 4
Assumption: AU-4 Mapping on all ports Root Cause: Fiber cut in the link from A to B
VC-12
ADM B VC-12 PT
TU AIS
Note: Only TU-AIS is reported on Node C (See Rule 4c)
LP RDI
LP-RDI on B is SSA58
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LOS
MS-RDI
HP-RDI
LP RDI
Alarm Propagation Examples (…contd.)
MS-AIS
LP RDI MS-RDI
HP-RDI
E1 E1
VC-12 VC-12
A CB
Example 5
Assumption: AU-4 Mapping on all ports Root Cause: Fiber cut in the link from A to B
VC-4
ADM B VC-4 PT
Note: Only AU-AIS is reported on Node C (See Rule 4c) LP-RDI on B is not reported (See Rule 3b)
AU AIS
TU AIS
59
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Invalid TU Pointers (1-1-2)
TU-LOP (1-1-2)
A DCB
E1
(2)
VC-12 (1-1-2)
Example 6
Assumption: AU-4 Mapping on all ports Root cause: NO XConnect on B, C & D for (1-1-2)
E1 (1)
E1 (1)
VC-12 (1-1-1)
LP RDI (1-1-2)
Note: Why E1(1) is shown?
LP-RDI is not reported on B (See Rule 3a)
Alarm Propagation Examples (…contd.)
60
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Invalid TU Pointers (1-1-2)
TU-LOP (1-1-2)
LP RDI (1-1-2)
Note: LP-RDI at node B is secondary suppressed
TU-AIS at node A is reported as terminating alarm
Alarm Propagation Examples (…contd.)
VC-12 (1-1-2)
A DCB
Example 7
Assumption: AU-4 Mapping on all ports Root cause: NO XConnect on C & D for (1-1-2)
E1 (1)
E1 (1)
VC-12 (1-1-1)
E1
(2)
VC-12 (1-1-2)
TU-AIS (1-1-2)
TU AIS (1-1-2)
LP RDI (1-1-2)
LP-RDI (1-1-2)
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Invalid TU Pointers (1-1-2)
TU-LOP (1-1-2)
LP RDI (1-1-2)
Note: K-L-M value need not remain same throughout a particular LP, alarms will
be reported accordingly on different objects
Alarm Propagation Examples (…contd.)
TU-AIS (1-1-2)
TU AIS (1-1-2)
LP RDI (1-1-2)
LP-RDI (1-1-2)
VC-12 (1-1-2)
A DCB
Example 8
Assumption: AU-4 Mapping on all ports Root cause: NO XConnect on C for (1-1-2)
E1 (1)
E1 (1)
VC-12 (1-1-1)
E1
(2)
VC-12 (1-1-2)
E1
(2)
VC12(1-1-2)
Invalid TU Pointers (1-1-
2)TU-LOP (1-1-2)
LP RDI (1-1-2)
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Invalid TU Pointers
(1-1-1)
TU-LOP
(1-1-1)
LP-RDI
(1-1-1)
Note: LP-RDI from A is not reported on B (See Rule 3b).
Why assumption on SLM?
Alarm Propagation Examples (…contd.)
A CB
VC-12(1-1-1)
VC-4 VC-12(1-1-2)VC-12(1-1-2)E1 (1)
E1 (2)
E1(2)
Example 9
Assumption: AU-4 Mapping on all ports, Root cause: NO XConnect on C for (1-1-1)
VC4 PT at node B,For each port, HP-SLM default action is “ignore SLM”
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LOS
MS-RDI
HP-RDI
LP RDI
TU AIS
LP RDI
MS-AIS
LP RDI MS-RDI
HP-RDI
Alarm Propagation Examples (…contd.)
VC-12VC-12
VC-12
E1 E1
A CB
D
Example 10 (with SNCP)
Assumption: AU-4 Mapping on all ports Root cause: Fiber-cut in the link from A to B
W A-B-C, P A-D-C
VC-12
Note: SNCP is always
uni-directional & for
Tejas, it is 1+164
www.mapyourtech.com65
Alarms: Animated Description
www.mapyourtech.com
SDH Alarms and Consequent Actions
RS-TIM
LOS
LOF RS-BIP
MS-EXC
MS-AIS
MS-BIPMS-RDI MS-REIMS-DEG
MST
RST
SPI
AU-LOPAU-AIS
MSA
HP-UNEQ
HPOM
HP-EXCHP-TIM
HP-BIPHP-RDI HP-REIHP-DEG
HPOM / HPT
TU-AISHP-PLM
TU-LOP
HPA
LP-UNEQ
LPOM
LP-EXCLP-TIM
LP-BIPLP-RDI LP-REILP-DEG
LPOM / LPT
LP-PLM
LPA
HP-LOM
66
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LOS
LINE
TRIB
PDH
NE LINE NE
LOS
MS-RDI
AU/TU-AIS
PDH-AISK2=XXXXX110
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
INTERRUPTION,HW TROUBLE,ATTENUATION
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LOF
LINE
TRIB
PDH
NE LINE NE
LOF
MS-RDI
AU/TU-AIS
PDH-AIS
A1,A2
K2=XXXXX110
PROBLEM ON FRAMEALIGNMENT WORD
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
68
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RS-TIM
LINE
TRIB
PDH
NE LINE NE
RS-TIM
MS-RDI
AU/TU-AIS
PDH-AIS
JO
K2=XXXXX110
RECEIVED REGENERATORSECTION TRACE
IDENTIFIER MISMATCH
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
69
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RS-BIP
LINE
TRIB
PDH
NE LINE NE
RS-BIP
B1ERRORED SIGNAL
NEAR END
PERFORMANCE
COLLECTION
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
70
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LINE
TRIB
PDH
LINE NE
MS-AIS
MS-AIS
MS-RDI
AU/TU-AIS
PDH-AISK2=XXXXX110
K2=XXXXX111TROUBLE ON THERECEIVED SIGNAL(LOS, LOF, RS-TIM)
MS-AIS
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
71
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MS-EXC
LINE
TRIB
PDH
NE LINE NE
MS-EXC
MS-RDI
AU/TU-AIS
PDH-AIS
B2
K2=XXXXX110
EXCESSIVE BITERROR RATE
( 1X10 E -3)
NEAR END
PERFORMANCE
COLLECTION
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
72
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MS-BIP
LINE
TRIB
PDH
NE LINE NE
MS-BIP
B2ERRORED SIGNALNEAR END
PERFORMANCE
COLLECTION
MS-REI
M1
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
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MS-RDI
LINE
TRIB
PDH
NE LINE NE
MS-RDI
MS-RDI
K2=XXXXX110TROUBLE ON THERX SIDE
(LOS, LOF. RS-TIM,MS-AIS, MS-EXC,
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
74
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MS-REI
LINE
TRIB
PDH
NE LINE NE
MS-REI
M1 FAR END
PERFORMANCE
COLLECTION
ERRORED SIGNAL
MS-REI
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
75
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MS-DEG
LINE
TRIB
PDH
NE LINE NE
MS-DEG
MS-REI
B2
M1
DEGRADATION
(1X10 E -5 1X10 E -9 )
NEAR END
PERFORMANCE
COLLECTION
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
76
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LINE
TRIB
PDH
NE LINE NE
AU-4 XC
AU-AIS
AU-AIS
PDH-AISG1 =XXXX100X
TROUBLE ON THERX SIDE
(LOS, LOF, RS-TIM,MS-AIS, MS-EXC,
HP-RDI
AU-AIS
AU/TU-AIS
AIS
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
77
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LINE
TRIB
PDH
NE LINE NE
AU-LOP
AU-LOP
PDH-AISG1 =XXXX100X
TROUBLE ON THEAU POINTER VALUE(WRONG SETTINGSDH/SONET, DEG,
HW FAILURE)
HP-RDI
AU/TU-AIS
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
H1,H2
78
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LINE
TRIB
PDH
NE LINE NE
HP-UNEQ
HP-UNEQ
C2 = 00000000AU-4 CHANNEL
NOT CONNETTED
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
79
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LINE
TRIB
PDH 140M
NE LINE NE
HP-TIM
G1 =XXXX100X
HP-TIM
HP-RDI
RECEIVED HIGHER PATH TRACEIDENTIFIER MISMATCH
HP-TIM
J1
PDH-AIS
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
80
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HP-BIP
LINE
TRIB
PDH 140M
NE LINE NE
ERRORED SIGNAL NEAR END
PERFORMANCE
COLLECTION
HP-BIP
B3
HP-BIP
HP-REI
G1 (1,2,3,4)
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
81
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HP-RDI
LINE
TRIB
PDH 140M
NE LINE NE
HP-RDI
TROUBLE ON THERECEIVED HP
(AU-AIS, AU-LOP, HP-TIM,HP-PLM, HP-EXC)
HP-RDI
HP-RDI
G1 =XXXX100X
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
82
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HP-REI
LINE
TRIB
PDH 140M
NE LINE NE
FAR END
PERFORMANCE
COLLECTION
ERRORED SIGNAL
HP-REI
HP-REI
HP-REI
G1 (1, 2, 3, 4)
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
83
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HP-DEG
LINE
TRIB
PDH 140M
NE LINE NE
NEAR END
PERFORMANCE
COLLECTION
HP-DEG
HP-DEG
HP-REI
G1 (1,2,3,4)
DEGRADATION
(1X10 E -5 1X10 E -9 ) B3
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
84
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HP-EXC
LINE
TRIB
PDH 140M
NE LINE NE
NEAR END
PERFORMANCE
COLLECTION
HP-EXC
HP-EXC
HP-RDI
EXCESSIVE BITERROR RATE
( 1X10 E -3)B3
G1 =XXXX100X
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
85
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LINE
TRIB
PDH
NE LINE NE
HP-PLM
HP-PLM
TU-AIS
PDH-AISG1 =XXXX100X
UNEXPECTED HIGHERPATH PAYLOD LABEL
HP-RDI
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
C2
86
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LINE
TRIB
PDH
1.5-2-34-45M
NE LINE NE
TU XC
TU-AIS
TU-AIS
TROUBLE ON THERX SIDE
(AU-AIS, AU-LOP,HP-TIM, HP-PLM)
TU-AIS
AIS
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
LP-RDI
V5 = XXXXXXX1PDH-AIS
AIS
87
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LINE
TRIB
PDH
1.5-2-34-45M
NE LINE NE
TU-LOP
TU-LOP
V5 = XXXXXXX1
TROUBLE ON THETU POINTER VALUE
(DEGRADATION,HW FAILURE)
TU-AIS
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
V1, V2
LP-RDI
PDH-AIS
AIS
88
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LINE
TRIB
PDH
1.5-2-34-45M
NE LINE NE
LP-TIM
V5 = XXXXXXX1
LP-TIM
LP-RDI
RECEIVED LOWER PATH TRACEIDENTIFIER MISMATCH
LP-TIM
J2
PDH-AIS
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
89
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LP-BIP
LINE
TRIB
PDH
1.5-2-34-45M
NE LINE NE
ERRORED SIGNAL NEAR END
PERFORMANCE
COLLECTION
LP-BIP
V5 (1, 2)
LP-BIP
LP-REI
V5 (3)
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
90
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LP-RDI
LINE
TRIB
PDH
1.5-2-34-45M
NE LINE NE
LP-RDI
TROUBLE ON THERECEIVED LP
(TU-AIS, TU-LOP, LP-TIM,LP-PLM, LP-EXC)
LP-RDI
LP-RDI
V5 = XXXXXXX1
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
91
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LP-REI
LINE
TRIB
PDH
1.5-2-34-45M
NE LINE NE
FAR END
PERFORMANCE
COLLECTION
ERRORED SIGNAL
LP-REI
LP-REI
LP-REI
V5 (3)
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
92
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LP-DEG
LINE
TRIB
PDH
1.5-2-34-45M
NE LINE NE
NEAR END
PERFORMANCE
COLLECTION
LP-DEG
LP-DEG
LP-REI
V5 (3)
DEGRADATION
(1X10 E -5 1X10 E -9 ) V5 (1, 2)
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
93
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LINE
TRIB
PDH
1.5-2-34-45M
NE LINE NE
LP-EXC
NEAR END
PERFORMANCE
COLLECTION
LP-EXC
LP-EXC
LP-RDI
EXCESSIVE BITERROR RATE
( 1X10 E -3)V5 (1, 2)
V5 = XXXXXXX1
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
94
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LINE
TRIB
PDH
1.5-2-34-45M
NE LINE NE
LP-PLM
LP-PLM
UNEXPECTED LOWERPATH PAYLOD LABEL
PDH-AIS
LP-RDI
V5 = XXXXXXX1
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
95
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LINE
TRIB
PDH
NE LINE NE
LP-UNEQ
LP-UNEQ
V5 (5, 6, 7) = 000TU CHANNEL
NOT CONNETTED
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
96
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LINE
TRIB
PDH
1.5-2M
NE LINE NE
HP-LOM
HP-LOM
V5 = XXXXXXX1
TROUBLE ON THEMULTIFRAME ALIGNMENT
WORD
TU-AIS
XXX = DETECTED
XXX = GENERATED
XXX = SENT BACK
XXX = MONITORED
AIS= SIGNAL PASSED THROUGH
H4
LP-RDI
PDH-AIS
AIS
97
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Regenerator Section Multiplex Section Higher Order Path Lower Order Path
A1/A2
J0
B1
K2
B2
M1
K2
C2
J1
B3
G1
G1
H4
C2
V5
J2
V5
V5
V5
V5
LOS
LOF
RS-TIM
RS-BIP
MS-AIS
MS-BIP
MS-REI
MS-RDI
AU-AIS
AU-LOP
HP-UNEQ
HP-TIM
HP-BIP
HP-REI
HP-RDI
TU-AIS
TU-LOP
TU-LOM
HP-PLM
LP-UNEQ
LP-TIM
LP-BIP
LP-REI
LP-RDI
LP-PLM
AIS
AIS
AIS
AIS
AIS
AIS
AIS
Error indicator alarm sent upstream
Alarm indicator sent upstream
Error/alarm detection
Œ
98
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Performance Monitoring
www.mapyourtech.com 100
Overhead Termination
LPT HPT MST RST RST MST HPT LPT
RSOH
MSOH
VC-4 POH
VC-12, VC-3 POH
2M, 34M Unit STM-n Unit 2M, 34M Unit
LPT: Lower-order Path terminationHPT: High-order Path termination
MST: Multiplex Section TerminationRST: Regenerator Section Termination
STM-n Unit
STM-n Unit or140M Unit
STM-n Unit or140M Unit
www.mapyourtech.com 101
Overhead Termination
STM-N unit
STM-N
TSI unit
RST MST HPT LPT
Crossconnect Level
VC-12 or VC-3 2M or 34M
2M or 34M unit
STM-N unit
STM-N
TSI unit
RST MST HPT
Crossconnect Level
VC-4 140M
140M unit
STM-N unit
STM-N
TSI unit
RST MST HPT HPT MST RST
Crossconnect Level
VC-12 or VC-3 STM-N
STM-N unit
STM-N unit
STM-N
TSI unit
RST MST RST
Crossconnect Level
VC-4 STM-N
STM-N unit
MST
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Performance Monitoring Point
102
• Physical Layer
• Section Layer
• Adaptation • High/Low-order Path Termination
www.mapyourtech.com 103
Performance Monitoring -Physical Layer-
• Optical InterfaceLDBC : Laser Diode Bias Current
• PDH InterfaceCV-L : Code Rule ViolationES-L : Errored SecondSES-L : Severely Errored Second
• External Clock InterfaceCV- * : Code Rule ViolationES- * : Errored Second)SES- * : Severely Errored Second
* : L or P
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Performance Monitoring -Section Layer-
• Regenerator (RS) and Multiplex (MS) Section ES- ** : Errored SecondSES- ** : Severely Errored SecondsBBE- ** : Background Block ErrorUAS- ** : Unavailable SecondsOFS- ** : Out of Frame Seconds (OOF)
• Multiplex Section Far-endES-MSFE : Errored SecondSES-MSFE : Severely Errored SecondsBBE-MSFE : Background Block ErrorUAS-MSFE : Unavailable Seconds
• Multiplex Section PSC : Protection Switching Count PSD : Protection Switching Duration ** : RS or MS
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Performance Monitoring -Adaptation-
• AU-4 Pointer
PJE (positive) : Pointer Justification Event (positive) PJE (negative) : Pointer Justification Event (negative)
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Performance Monitoring -Path Termination-
• High/Low-order Path (receiving direction)ES- ** : Errored SecondSES- ** : Severely Errored SecondsBBE- ** : Background Block ErrorUAS- ** : Unavailable Seconds
• High/Low-order Path (transmitting direction)ES- ** FE : Errored SecondSES- ** FE : Severely Errored SecondsBBE- ** FE : Background Block ErrorUAS- ** FE : Unavailable Seconds
** :
HO or LO
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Terms and Definitions(used by error performance)
EDC : Error Detection Code
Block : block
EB : Errored Block
Defect : defect
ES : Errored Second
SES : Severely Errored Second
BBE : Background Block Error
CV : Code Violation
UAS : Unavailable Second
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BIP-8 of VC-4
1
2
2348
1
1
1
1
2
2
2
2
3
3
3
3
4
4
4
4
5
5
5
5
6
6
6
6
7
7
7
7
8
8
8
82349
31
262
2
263
2348 2349
Group of 8 bits
VC-4
261
B lo c k ( 1 8 7 9 2 b i t s / b l o c k ) B3
BIP-8 check sequence
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Terms and Definitions(used by error performance)
EDC : Error Detection Code
Block : block
EB : Errored Block
Defect : defect
ES : Errored Second
SES : Severely Errored Second
BBE : Background Block Error
CV : Code Violation
UAS : Unavailable Second
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Terms and Definitions(used by error performance)
EDC : Error Detection Code
Block : block
EB : Errored Block
Defect : defect
ES : Errored Second
SES : Severely Errored Second
BBE : Background Block Error
CV : Code Violation
UAS : Unavailable Second
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Generation and Detection of SDH Performance
111
Bit Error Generation Mechanism
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
Notice: The Sequence of descramble& BIPNotice: The Sequence of descramble& BIP
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Generation and Detection of SDH Performance
112
B1
B2
B3
V5
RSTMSTHPTLPT LPTHPTMSTRST
Errors occurring in Low order path will not be detected in High order path, High order bit errors will trigger Low order errors.
Error Detection and Report
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Generation and Detection of SDH Performance
113
Terms
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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Generation and Detection of SDH Performance
114
Term Description
FESES Far end severely errored second, in which an SES event detected at the remote end.
CSES Consecutive severely errored second, in which the SES events consecutively occur, but last less than 10 seconds.
FECSES Far end consecutive severely errored second, in which a CSES 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.
Terms
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Generation and Detection of SDH Performance
115
Adjust pointers as required in practice, so as to tolerate rate
asynchronization and phase difference of payload signals.
That is, perform pointer justification on information payloads
to make the payloads synchronous with the STM-N frame
Mechanism
Administrative unit pointer (AU_PTR)
Tributary unit pointer (TU_PTR)
Sort
Pointer Justification
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Generation and Detection of SDH Performance
116
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:
Name
Byte 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 InfoInformation =
container
Positive H3 H3 H3 Stuffing Stuffing Stuffing Information< container
Negative Info Info Info Info Info Info Information> container
Generation Mechanism of AU Pointer Justification
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Generation and Detection of SDH Performance
117
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
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 Justification
Detection and Reporting of Pointer Justification
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Relationship between Alarms and Performance
118
Item Performance Event Alarm Event
Local end Remote end Local end Remote end
RS RSBBE - B1_OVER -
MS MSBBE MSFEBBE B2_OVER MS_REI
HP HPBBE HPFEBBE B3_OVER HP_REI
LP LPBBE LPFEBBE BIP_OVER LP_REI
Functions of alarm and performance for bit error threshold crossing
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.
Relationship
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Relation between ES, SES and BBEB
lock
sin
1se
c.p
erio
d
30 %
1 sec.
ESSES
EB} BBEnonEB
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Terms and Definitions(used by error performance)
EDC : Error Detection Code
Block : block
EB : Errored Block
Defect : defect
ES : Errored Second
SES : Severely Errored Second
BBE : Background Block Error
CV : Code Violation
UAS : Unavailable Second
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10 sec. 10 sec.< 10 sec.
Unavailability detected Availability detected
Unavailable period Available period
Error-free secondSeverely errored second
SESErrored second
ES
Unavailable Second
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1 day
(Yesterday)
Current 1 day (Today)
data update : every 1 min.
0 : 00 0 : 00
TCA (Threshold Crossing Alert)
1 day accumulation
32 periods with zero suppression(32) (2) (1)
15 min.
hh : 15n hh : 15(n+1)Current 15 min.
data update : every 1 min.
15 minute accumulation
TCA (Threshold Crossing Alert)
Storage of PM data
timepast future
0*
*0
*0
*0
00
00
00
00
00
00
0△
00
00
**
0*
*0
*0
*0
00
00
0△
00
00
**
item aitem b
item x
item y
item aitem b
item x
item y
memoryold new
Zero Suppression
all zero data with time stamp of △ occurrence
Zero Suppression
PM items of one facility
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Bit error defects family
123
EXC = EXCessively errored signal DEG = DEGraded signal CMI = Code Mark Inversion
All members of the [large] family of bit error defects have a common origin errors in the transmission/reception of a signal.
SDH calculates a parity check and places the results in the overhead. Occurs in both Tx and Rx. A difference indicates a bit error in transmission/reception
Another detection mechanism is for electrical signals An invalid sequence is a code violation
PPI-EXC and ES-CMI defect originate from code violations.
SDH paths and sections may have EXC and DEG defects [Different degrees of errors] EXC represent an ‘EXCessive’ number of bit errors – the signal is so badly errored as to be unusable
EXC defects represent a bit error ratio of 10-3 or 10-4. EXC results in a protection switch at the closure point of a sub-network connection and may be
configured to insert AIS and RDI. DEG defects represent a bit error ratio of 10-5 or less
DEG does not result in a protection switch or raising of any consequent action.
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What is Performance Monitoring
124
Performance monitoring is used to measure Traffic QualityHow? – By counting anomalies and defects.
Why are they needed?To diagnose faults in a network OR detect occurrence of dribbling errors.Measure a networks performance and its service capability.
At the edge of the network Within the network
Check service level agreements for end customers and find out whether they have been satisfied or breached.
Reporting performance monitoringNE collects and logs PMs continuously for all connections.EC-1 collects PMs from all NEs in span of control. INM collects PMs from the complete network.
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Performance Monitoring Points
125
Performance Monitoring Points [PMPs] are points at which software collects performance monitoring [PM]
data. The PM data is a measure of the quality of the transmission path at that point.
PDH End User
LP_NE V5, B3
LP_FE V5, G1
TU_PJE
Vc-12
Vc-12
PPI_CV
Vc-4 Vc-4
STM-NRS-OOF A1, A2
RS-NE B1
MS_NE B2
MS_FE M1
AU_PJE
HP_NE B3
HP_FE G1
Optical Link via Network
PDH End User
NE1NE2
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Table of PM points
126
PMs count will occur at the same points as where alarms will occur FE[Far End] PMs are associated with the RDI defect category.
The destination you are sending to has received your signal in a defective state.
PMP-Type Byte DefectsRS-OOF A1, A2
RS-NE B1 RS-LOS, RS-LOF
MS_NE B2 All RS defects, MS-AIS, MS-EXC
MS_FE M1 MS-RDI
AU_PJE N/A N/A
HP_NE, HPOM_NE
B3 All RS, MS defects, AU-AIS, AU-LOP, HP-LOM, HP-TIM, HP-PLM, HP-EXC
HP_FE, HPOM_FE G1 HP-RDI
TU_PJE N/A N/A
LP_FE
LPOM_FE
G1[VC-3]
V5(b3[VC-12]
HP-RDI, LP-RDI
LP_NE
LPOM_NE
B3[VC-3]
V5(b1-b2[VC-12]
All RS, MS, AU, HP defects, TU-AIS, TU-LOP, LP-TIM, LP-PLM, LP-EXC, INT-LO-BUFFER
ES-CV N/A ES-LOS
PPI-CV N/A PPI-LOS
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BIP Errors vs Block Errors
127
B1 is an 8 bit parity byte, calculated across the complete SDH frame [2430 bytes for an STM-1 signal].
B1 byte is generated/terminated at every NE. ANSI specifies BIP ETSI/ITU specifies Block Errors The B1 Byte is treated as 1 block The B1 Byte is treated as BIP-8 [since it has 8 bits]
Example
0 1 0 1 0 1 0 1
Transmitted
0 1 1 1 0 1 0 1
0 1 1 1 0 0 0 1
0 0 1 0 0 1 1 0
1 0 1 0 1 0 1 0
Received
= 1 Block Error, = 2 BIP Errors
= 1 Block Error, = 1 BIP Error
= 1 Block Error, = 5 BIP Errors
= 1 Block Error, = 8 BIP Errors
= Bit Error
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Definition of BBE, ES, SES, UAS
128
Background Block Error [BBE]A Background Block Error [BBE] is a single errored Block in the SDH
frame, not occurring as part of an SES or a UAS. Errored Second [ES]
An Errored Second [ES] is a second during which at least one anomaly or one defect occurs, but not occurring as part of a UAS.
Severely Errored Second [SES]A Severely Errored Second [SES] is a second during which at least ‘X’
anomalies or one defect occurs, but not occurring as part of a UAS. By definition an SES is always an ES.
Unavailable Second [UAS]An Unavailable Second is a second during which the signal is
unavailable. It becomes unavailable at the onset of 10 consecutive seconds that qualify as SES, and continue to be unavailable until the onset of 10 consecutive seconds that do not qualify as SES.
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How to interrupt SES and UAS
129
The difference between SES and UAS is conceptually difficult to understand. Therefore it is better clarified through the use of a diagram. Unavailable periods/detection and available periods/detection are indicated.
<10secs
Unavailability Detected
10secs <10secs
Unavailable Period
Availability Detected
Available Period
10secs
= SES = Non SES
Available Period
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Processing of B1 byte
130
This can be broken down into activities performed in hardware and software.
Calculate B1 block errors
Determine RS defects
1- Second Filter
15-Minute Filter
24-Hour Filter
SDH Frame
SDH Frame
Frame B1 errors
Frame RS defects, LOS, LOF
1- second BBE, ES, SES, UAS
15-minute BBE, ES, SES, UAS
24-hour BBE, ES, SES, UAS
15-Minute PM Counts
TIME BBE ES SES UAS00:00 3 3 1 000:15 5 4 0 000:30 1 1 0 0
24-Hour PM Counts
BBE ES SES UAS 40 33 0 0 34 16 20 20 21 4 2 0
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Calculating B1 block errors.
131
The calculation of B1 block errors occurs in hardware.Conceptually this can be understood via a diagram.
Frame X Frame X+1 Frame X+2
Calculate expected B1 byte
Compare actual with expected B1 byte
Expected B1 byte
Actual B1 byte
B1 errors
}
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1- Second Filter
132
1-Second Filter
B1 Errors (x) BBE ES SES UASx = 0 0 0 0 00 < x < 2400 x 1 0 0x >= 2400 (< 10 secs) 0 1 1 0x >= 2400 (> 10 secs) 0 0 0 1
Defects BBE ES SES UASNo Defects 0 0 0 0LOS, LOF (< 10 secs) 0 1 1 0LOS, LOF (> 10 secs) 0 0 0 1
1-Second filter
Frame B1 errors
Frame RS defect, LOS,
LOF
1- second BBE, ES, SES, UAS
SDH Frame B1 Errors/Defects
DATE TIME FRAME B1 Errors Defects01/01/2000 00:00:00 0001 0 -01/01/2000 00:00:00 0002 0 -01/01/2000 00:00:00 0003 1 - “ “ “ . . “ “ “ . . “ “ “ . .01/01/2000 00:00:00 7998 0 -01/01/2000 00:00:00 7999 0 -01/01/2000 00:00:00 8000 0 - ---- TOTAL B1 Errors (x) = 0001
} 1-Second PM Counts
DATE TIME BBE ES SES UAS01/01/2000 00:00:00 1 1 0 001/01/2000 00:00:01 x x x x01/01/2000 00:00:02 x x x x
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15-Minute Filter
133
1- second BBE, ES, SES, UAS 15-
Minute Filter
15-Minute BBE, ES, SES, UAS
15-Minute PM Counts
DATE TIME BBE ES SES UAS01/01/2000 00:00 3 3 1 001/01/2000 00:15 x x x x01/01/2000 00:30 x x x x
1-Second PM Counts
DATE TIME BBE ES SES UAS01/01/2000 00:00:00 1 1 0 001/01/2000 00:00:01 0 0 0 001/01/2000 00:00:02 0 1 1 0 “ “ . . . . “ “ . . . . “ “ . . . .01/01/2000 00:14:57 2 1 0 001/01/2000 00:14:58 0 0 0 001/01/2000 00:14:59 0 0 0 0
}
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24 Hour Filter
134
1- second BBE, ES, SES, UAS 24-Hour
Filter
24-Hour BBE, ES, SES, UAS
}24-Hour PM Counts
DATE BBE ES SES UAS01/01/2000 40 33 3 002/01/2000 x x x x03/01/2000 x x x x “ . . . . “ . . . . “ . . . .
1-Second PM Counts
DATE TIME BBE ES SES UAS01/01/2000 00:00:00 1 1 0 001/01/2000 00:00:01 0 0 0 001/01/2000 00:00:02 0 1 1 0 “ “ 30 . . . “ “ . 30 1 . “ “ 4 . . .01/01/2000 23:59:57 0 0 1 001/01/2000 23:59:58 5 1 0 001/01/2000 23:59:59 0 0 0 0
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TIME B1 Errors Defects1 5 -2 50 -3 500 -4 5000 -5 0 LOS6 40 LOS7 400 LOS8 4000 LOS9 2500 LOF10 2700 -11 3000 -12 4000 -13 5000 -14 6000 -15 7000 -16 0 -17 50 -18 0 -19 100 -20 0 -21 30 -22 0 -23 35 -24 0 -25 0 -26 0 -27 40 -28 0 LOF29 0 -
BBE= 5 ES= 1 SES= UAS= BBE= 50 ES= 1 SES= UAS= BBE= 500 ES= 1 SES= UAS= BBE= ES= 1 SES= 1 UAS= BBE= ES= 1 SES= 1 UAS= BBE= ES= 1 SES= 1 UAS= BBE= ES= 1 SES= 1 UAS= BBE= ES= 1 SES= 1 UAS= BBE= ES= 1 SES= 1 UAS= BBE= ES= 1 SES= 1 UAS= BBE= ES= 1 SES= 1 UAS= BBE= ES= 1 SES= 1 UAS= BBE= ES= 1 SES= 1 UAS= BBE= ES= SES= UAS= 1 BBE= ES= SES= UAS= 1 BBE= ES= SES= UAS= 1 BBE= ES= SES= UAS= 1 BBE= ES= SES= UAS= 1 BBE= ES= SES= UAS= 1 BBE= ES= SES= UAS= 1 BBE= ES= SES= UAS= 1 BBE= ES= SES= UAS= 1 BBE= ES= SES= UAS= 1 BBE= ES= SES= UAS= 1 BBE= ES= SES= UAS= 1 BBE= ES= SES= UAS= BBE= 40 ES= 1 SES= UAS= BBE= ES= 1 SES= 1 UAS= BBE= ES= SES= UAS=
TOTAL BBE= 595 ES= 15 SES= 11 UAS= 12
B1 errors5000 > 2400 [<10 secs]
DefectsLOS, LOF (< 10 secs)
Unavailable Period
B1 errorsX > 2400 [>10 secs]AND / ORDefectsLOS, LOF [>10secs]
Unavailability
Detected
Availability
DetectedB1 errorsX < 2400 [>10secs]AND / ORDefectsNo Defects [>10secs]
135
Accumulation of PMs over time
10 Second
Period
2 Seconds that
qualify as SES
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FAQs
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Question and Answers
137
What is the difference between an anomaly and a defect? Anomaly is a single occurrence of, or commencement of a condition Defect is a persistent or repeated occurrence of an anomaly
What is the main difference between a POM alarm and a LO or HO alarm? LPs / HPs are present on termination POMs are present when traffic is un-terminated
What is the main principle behind masking? Present alarm closet to source Reduce the amount of fault analysis and alarm presentation
A car fail alarm is raised on a PIU, What should you do? This alarm needs to be cleared first because it will mask all other alarms raised on
the card/slot instance What is the difference between a regenerator and a multiplexer?
Regenerator terminates the RSOH, MSOH + payload continue, regenerator generates new OH
Multiplexer fulfils the same function of a regenerator and also terminates / generates a MSOH
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Question and Answers
138
What alarms does the Multiplex Section Termination give?Provides pointer processing and gives AU alarms
Where are the Low Path Termination points?On PDH tributaries
If an unprotected limb has two POMs present which one is active the Rx or the Tx?Rx is active
In a protected connection is a limb has a HPT or LPT present can HPOM/LPOM also be active?Yes
Which bytes are responsible for the reporting of a LOF alarm, what section overhead are they found?A1 and A2 –In RSOH
Where is AIS reported in relation to a defect?AIS is reported downstream from a defect, a user would look upstream to
resolve the issue
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Question and Answers
139
Why is there no RS-AIS alarm? Possibly redundancy [Like the TIM alarms which only has RS-TIM] Could also be that RS alarms on regenerators are passive and operate as a pass
through. Multiplexers drop traffic and are better therefore to address issue How many consequent actions are there and what are they?
AIS, RDI/REI and protection switches Which alarm is more serious, RDI or REI?
RDI is more serious What type of cards produce CMI alarms?
Electrical cards [comes from Code Mark Inversion line coding] What consequent actions does a DEG alarm produce?
It doesn’t What type of payload would you expect on the raising of a UNEQ alarm?
0 What bytes carry PM information and where are they calculated?
B1, B2 and B3. Calculated in hardware
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• Various presentation collected from Internet {Huawei,Tejas,Nortel & Marconi) available free of cost
• www.mapyourtech.com• www.google.com
For further queries do reach on www.mapyourtech.com
140
References
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Thank You!