sdh/sonet alarms & performance monitoring

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SDH/SONET ALARMS & PERFORMANCE MONITORING

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• Standards• Alarms Introductions and Examples• Performance Monitoring Parameters• FAQs

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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

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Standards


Alarms Introductions and Examples


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

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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


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)


(PTE)


(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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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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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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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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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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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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Uplink Signal Flow


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 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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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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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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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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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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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


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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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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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

45

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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

46

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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

50

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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

14

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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


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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HP-RDI

HP- UNEQ


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


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


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


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

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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)


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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


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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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


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?


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


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


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

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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


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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


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


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


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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


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


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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


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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


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


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


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


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


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


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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


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


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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


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


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HP-EXC

LINE

TRIB

PDH 140M

NE LINE NE

NEAR END

PERFORMANCE

COLLECTION

HP-EXC

HP-EXC

HP-RDI


( 1X10 E -3)B3

G1 =XXXX100X

XXX = DETECTED

XXX = GENERATED

XXX = SENT BACK

XXX = MONITORED


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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


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


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


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


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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


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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


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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


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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


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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


( 1X10 E -3)V5 (1, 2)

V5 = XXXXXXX1

XXX = DETECTED

XXX = GENERATED

XXX = SENT BACK

XXX = MONITORED


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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


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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


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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


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


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


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


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


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


Performance Monitoring -Adaptation-

• AU-4 Pointer

PJE (positive) : Pointer Justification Event (positive) PJE (negative) : Pointer Justification Event (negative)


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


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


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




Block : block

EB : Errored Block

Defect : defect

ES : Errored Second



CV : Code Violation


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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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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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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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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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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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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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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


Relation between ES, SES and BBEB

lock

sin

1se

c.p

erio

d

30 %

1 sec.

ESSES

EB} BBEnonEB




Block : block

EB : Errored Block

Defect : defect

ES : Errored Second



CV : Code Violation



10 sec. 10 sec.< 10 sec.

Unavailability detected Availability detected

Unavailable period Available period

Error-free secondSeverely errored second

SESErrored second

ES

Unavailable Second


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



= 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


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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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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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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http://www.google.com/


Thank You!

sdh/sonet alarms & performance monitoring

Presentations & Public Speaking