107079856 otn for newbies

OTN NEWBIES

1

FOREWORD

According to the ITU-T Recommendation G.709, an Optical Transport Network (OTN) is composed of a set of optical network elements connected by optical fiber links. The network provides functionality of transport, multiplexing, routing, management, supervision, and survivability of optical channels carrying client signals.

This architecture can be seen as a combination of the advantages of SDH/SONET technology with the flexibility of DWDM. Using OTN, the OAM&P functionality of SDH/SONET is applied to DWDM optical networks.

Compared to SDH/SONET, OTN has the following advantages:

• Stronger error correction mechanisms

• More levels of tandem connection monitoring

• Transparent transport of client signals

• Switching scalabilityIntroduction

Page2

ABOUT THIS COURSE

This course is based on the following ITU-T

recommendations:

ITU-T G.709

ITU-T G.805

ITU-T G.806

ITU-T G.798

Page3

LEARNING GUIDE

Just little Basics

4

CONTENTS

1. OTN Introduction

2. Typical OTN Scenarios

Page5

CONTENTS

1. OTN Introduction

1.1 OTH

1.2 OTN Port Structure

1.3 Multiplexing/Mapping Principles and Bit Rates

1.4 Overhead Description

1.5 Maintenance Signals and Functions of Different Layers

1.6 Alarms and Performance Events

Page6

OTN

Optical transport network (OTN)

An OTN network is composed of a set of

optical NEs connected by optical fiber links.

These NEs are able to provide functions

such as transport, multiplexing, routing,

management, supervision, and protection

(survivability) of client signals, according to

the requirements specified in REC. G.872.

Page7

FEATURES OF OTN

Compared with SDH and SONET networks, an OTN

network has the following features:

Ultra capacity with high accuracy, T-bit/second per fiber

over DWDM lines

Service transparency for client signals

Asynchronous mapping, powerful FEC function, simplified

network design, and reduced costs

Compared with traditional WDM networks, an OTN

network has the following features:

Enhanced OAM and networking capabilities for all services

Dynamic electrical/optical-layer grooming

Page8

OTN STANDARD SYSTEM

Structure

OTN

OTN network structure G.872

ASON network structure G.8080

Structure and

mapping Generic frame protocol (GFP) G.7041

Link capacity adjustment scheme (LCAS) for virtual concatenation signals G.7042

Ports on an OTN network G.709

Equipment

functions

and

features

Features of function blocks of equipment on an OTN network G.798

Transport network equipment features: description methods and general functions G.806

Physical-layer

features Optical ports for intra-office systems G.693

Optical security rule and requirements in an optical transport system G.664

Physical-layer ports on an OTN network G.959.1

Network

protection

Linear protection on an OTN network G.873.1

Ring protection on an OTN network G.873.2

Jitter and

performance

Jitter and shift control on an OTN network G.8251

Bit error performance parameters and specifications on international channels of multiple carriers on an OTN network G.8201

Equipment

management

Management features of NEs on an OTN network G.874

OTN network: Protocol-neutral management information model for the network element G.874.1

9

OTN NETWORK LAYERS AND PORT STRUCTURE

OPUk: optical channel payload unit-k

ODUk: optical channel data unit-k

OTUk: completely standardized optical

channel transport unit-k

OTUkV: functionally standardized

Optical channel transport unit-k

OCh: optical channel with full

functionality

OChr: optical channel with reduced

functionality

OMS: optical multiplex section

OTS: optical transmission section

OPS: optical physical section

OTM: optical transport module

Page10

ODUk (ODUkP and ODUkT)

OPUk

OTUk OTUkV OTUk OTUkV

OCh OChr

OMSn

OTSn OPSn

IP/MPLS ATM Ethernet STM-N

OTM-0.m

OTM-nr.m

OTM-n.m

OTM-N.M CONTAINMENT RELATIONSHIPS

“n” represents the maximum number of wavelengths that can be supported at the lowest bit rate

supported by the wavelengths. “m” equals 1, 2, 3, 12, 23, or 123.

OTS_OH, OMS_OH, OCh_OH and COMMS OH information fields are contained in the OOS.

The optical supervisory channel (OSC) is used to transmit OOSs.

Page11

OCCp OCCp OCCp

OCh payload

ODUk FEC OH

OPUk OH

Client signal

OPUk payload OH OPUk

ODUk

OTUk[V]

OCh

OCG-n.m

OTM-n.m OTSn OH

OMSn OH

OC

Co

OChOH

OC

Co

OC

Co

OMU-n.m

Non

-associa

ted O

H

OOS

Com

mon

managem

ent

OH

OT

M-n

. m

OTM overhead signal (OOS)

l 2

l 1

l n

l OSC

OTM-NR.M CONTAINMENT RELATIONSHIPS

Fixed channel spacing, irrelevant to the signal rate

1 < n ≤ 16; m = 1, 2, 3, 12, 23, or 123

Without optical supervisory channels

Page12

OCCp OCCp OCCp

OCh payload

ODUk FEC OH

OPUk OH

Client signal


ODUk

OTUk[V]

OChr

OCG-nr.m

OTM-nr.m

OT

M-1

6r.

m

l 2

l 1

l 16

OTM-0.M CONTAINMENT RELATIONSHIPS

The OTM 0.m supports a non-colored optical channel on a single optical span with

3R regeneration at each end.

m = 1, 2, or 3

Without optical supervisory channels

Page13

OCh payload

ODUk FEC OH

OPUk OH

Client signal


ODUk

OTUk[V]

OChr

OTM-0.m OPS0

OT

M-0

.m

OTN PORTS

User to network interface (UNI)

Network node interface (NNI)

Inter-domain interface (IrDI)

Intra-domain interface (IaDI)

Between equipment provided by different vendors (IrVI)

Within subnet of one vendor (IaVI)

The completely standardized OTUk is used at OTM IrDIs and OTM IaDIs.

The partly standardized OTUk is used at OTM IaDIs.

Page14

OTM

UNI

OTM NNI

IaDI-IrVI

OTM NNI

IaDI-IaVI

OTM NNI

IaDI-IaVI

Network Operator B

Vendors X Vendors Y

OTM

NNI

IrDI

Network

Operator

C

USER

A

CONTENTS

1. OTN introduction

1.1 Optical transport hierarchy

1.2 OTN interface structure

1.3 Multiplexing/mapping principles and bit rates

1.4 Overhead description

1.5 Maintenance signals and function for different layers

1.6 Alarm and performance events

Page15

OTN MULTIPLEXING AND MAPPING STRUCTURE

Page16

Mapping

Multiplexing

ODTUG3

ODTUG2

OChr

OChr

OChr

OCh

OCh

OCh

OTU3[V]

OTU2[V]

OTU1[V]

Client signal

Client signal

OPU3 ODU3

OCCr

OCCr

OCCr

OCC

OCC

OCC

OCG-nr.m

1 ≤ i+j+k ≤ n

OCG-n.m

1 ≤ i+j+k ≤ n

OPU2 ODU2

1 OPU1 ODU1

OTM-nr.m

OTS, OMS, OCh, COMMS OSC OOS

OTM-n.m

4

1

1 4

16 1

1 1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

i

j

k

i

j

1

Clie

nt s

ign

al

1

OTM-0.m

k

OTN Multiplexing and Mapping Structure

17

OTN Multiplexing and Mapping Structure

18

O

PU

flex

OPU4

OPU3

OPU2

OPU0

OPU1

Client service rate

1.238G

2.488G

9.995G

40.149G

104.134G

10.312G OPU2e

LO OPU

OP

Ufle

x(G

FP

)

OP

Ufle

x

OP

Ufle

x

LO ODU

New LO ODU signals

1.25G ODU0

10.3G ODU2e

104G ODU4

ODUflex

OTN Service Bearing Capability (LO

ODU)

19

OTN LINE BEARING CAPABILITY

(HO ODU)

OP

U3e2/2

1

(OD

U0

, OD

U1

, OD

U2

, OD

U2

e, O

DU

flex)

OP

U3/2

0

(OD

U1

, OD

U2

)

OP

U2/2

1

(OD

U0

, OD

U1

, OD

Ufle

x)

OP

U2/2

0

(OD

U1

)

OP

U4

/21

(OD

U0

, OD

U1

, OD

U2

, OD

U2

e, O

DU

3, O

DU

3e

2, O

DU

flex)

OP

U3/2

1

(OD

U0

, OD

U1

, OD

U2

, OD

U2

e, O

DU

flex)

OP

U1

(O

DU

0)

LO ODU rate

ODU0

ODU1

ODU2

ODU3

ODU4

ODU2e

HO OPU

OD

Ufle

x

OD

Ufle

x

OD

Ufle

x

OD

Ufle

x(G

FP

)

ODU3e2

New HO ODU signals

2.5G ODU1

41.7GG ODU3e2

(G.sup43)

104G ODU4

Signals with extended

capabilities

– 10G ODU2

– 40G ODU3

20

OTUK FRAME RATE

OTU Type OTU Nominal Bit Rate OTU Bit Rate Tolerance

OTU1 255/238 x 2488320 kbit/s

20 ppm

OTU2 255/237 x 9953280 kbit/s

OTU3 255/236 x 39813120 kbit/s

OTU4 255/227 x 99532800 kbit/s

Note 1: The nominal OTUk rates are approximately 2666057.143 kbit/s (OTU1), 10709225.316

kbit/s (OTU2), 43018413.559 kbit/s (OTU3) and 111809 973.568 kbit/s (OTU4).

Note 2: OTU0, OTU2e and OTUflex are not specified in this recommendation. ODU0 signals

are transported over ODU1, ODU2, ODU3 or ODU4 signals, ODU2e signals are transported

over ODU3 and ODU4 signals, and ODUflex signals are transported over ODU2, ODU3 and

ODU4 signals.

OTUk rate = 255/(239 - k) x STM-N frame rate

ODUK FRAME RATE

ODU Type ODU Nominal Bit Rate ODU Bit Rate Tolerance

ODU0 1244160 kbit/s

20 ppm

ODU1 239/238 x 2488320 kbit/s

ODU2 239/237 x 9953280 kbit/s

ODU3 239/236 x 39813120 kbit/s

ODU4 239/227 x 99532800 kbit/s

ODU2e 239/237 x 10312500 kbit/s 100 ppm

ODUflex for CBR

client signals

239/238 x Client signal bit rate Client signal bit rate tolerance, with a

maximum of 100 ppm

ODUflex for GFP-F

mapped client

signals

Pre-set bit rate 20 ppm

Note: The nominal ODUk rates are approximately 2498775.126 kbit/s (ODU1), 10037273.924 kbit/s

(ODU2), 40319218.983 kbit/s (ODU3), 104794445.815 kbit/s (ODU4) and 10399525.316 kbit/s

(ODU2e).

ODUk rate = 239/(239 - k) x STM-N frame rate

OPUK FRAME RATE

OPU Type OPU Payload Nominal Bit Rate OPU Payload Bit Rate Tolerance

OPU0 238/239 x 1244160 kbit/s

20 ppm

OPU1 2488320 kbit/s

OPU2 238/237 x 9953280 kbit/s

OPU3 238/236 x 39813120 kbit/s

OPU4 238/227 x 99532800 kbit/s

OPU2e 238/237 x 10312500 kbit/s 100 ppm

OPUflex for CBR client

signals

Client signal bit rate Client signal bit rate tolerance, with a

maximum of 100 ppm

OPUflex for GFP-F

mapped client signals

238/239 x ODUflex signal rate 20 ppm

OPU1-Xv X x 2 488 320 kbit/s

20 ppm

OPU2-Xv X x 238/237 x 9953280 kbit/s

OPU3-Xv X x 238/236 x 39813120 kbit/s

Note: The nominal OPUk payload rates are approximately 1238954.310 kbit/s (OPU0 Payload), 2488320.000 kbit/s

(OPU1 payload), 9995276.962 kbit/s (OPU2 payload), 40150519.322 kbit/s (OPU3 payload), 104355975.330 (OPU4

payload) and 10356012.658 kbit/s (OPU2e payload). The nominal OPUk-Xv payload rates are approximately X x

2488320.000 kbit/s (OPU1-Xv payload), X x 9995276.962 kbit/s (OPU2-Xv payload) and X x 40150519.322 kbit/s

(OPU3-Xv payload).

OPUk payload rate = 238/(239 - k) x STM-N frame rate

ODUK (TDM)

Low-rate ODUk signals are multiplexed into

high-rate ODUk signals using time-division

multiplexing:

A maximum of four ODU1 signals are multiplexed

into one ODU2 signal using time-division

multiplexing.

Hybrid j (j 4) ODU2 and 16-4j ODU1 signals are

multiplexed into one ODU3 signal using time-division

multiplexing.

Multiple LO ODUi[j] signals at different levels are

multiplexed into one HO ODUk signal.

Page24

ODU1 MULTIPLEXED INTO ODU2

ODTU12: optical channel data tributary unit 1 into 2

ODTUG2: optical channel data tributary unit group 2

JOH: justification overhead

Page25

ODU1

OH ODU1 ODU1 payload

ODTU12 JOH

ODU1 ODTU12

ODU2 OH

OPU2

OH

ODU2 payload

OPU2

ODU2

ODTU12 JOH

ODU1 ODTU12

JOH ODU1 ODTUG2

ODTUG2

OPU2 payload

ODU1 MULTIPLEXED INTO ODU2

ODU1 floats in one quarter of the OPU2 payload area.

An ODU1 frame travels cross multiple ODU2 frame boundaries.

Page26

OTU2 OTU2 FEC

Client-layer signal

(STM-16, ATM, or GFP) ODU1

ODU1OH

Alignment

ODU2

x4

Client Layer Signal (for example, STM-16) ODU1 OH O

PU

1 O

H


PU

1 O

H


PU

1 O

H

Client-layer signal (STM-16, ATM, or GFP) ODU1 OH

ODU2 OH

OP

U2 O

H

OPU2 Payload ODU2 OH

Alignment

OP

U2 O

H OTU2

OH


PU

1 O

H


PU

1 O

H


PU

1 O

H

Client-layer signal (STM-16, ATM, or GFP) ODU1 OH

OP

U1 O

H

Alignment

Alignment

OP

U1 O

H

OP

U1 O

H

ODU1 AND ODU2 MULTIPLEXED INTO ODU3



Page27

ODU1 OH ODU1 ODU1 payload

ODTU13 JOH

ODU1 ODTU13

ODU3 OH

OPU3 OH

ODU3 payload

OPU3

ODU3

ODTU23 JOH

ODTU23 JOH

ODU1 ODTUG3

ODTUG3

OPU3 payload

ODU2 OH ODU2 ODU2 payload

ODTU23 JOH

ODU2 ODTU23

ODTU13 JOH

ODU2 ODTU13 JOH

ODU2 ODU1

OH

Payload Area

client data

stuff

server frame or multi-frame

0

memory

Pserver?

Pserver

client data

indication =

read/write

enable

payload area

frame start

clock

Cm(t)

enable

GMP can automatically adapt CBR services to an OTN container. It is the key

technology for an OTN network to bear multiple services.

Service rate information transmitted in overheads

Sigma-delta algorithm

M byte bit width

Separation of data and clocks

GMP Mapping

28

ODUflex

OH

OH Services with

a fixed bit rate

Client signals

Packet services

Client services

OH

GMP TSi TSj

ODUflex

OH BMP

TSi TSj

GMP

GFP

Map CBR services to ODUflex services using synchronized packet encapsulation.

Map packet services to ODUflex services using GFP.

Map ODUflex services to HO OPUk services using GMP.

ODUflex

29

CONTENTS

1. OTN introduction

1.1 Optical transport hierarchy

1.2 OTN interface structure

1.3 Multiplexing/mapping principles and bit rates

1.4 Overhead description

1.5 Maintenance signals and function for different layers

1.6 Alarm and performance events

Page30

OOS

TTI: trail trace identifier

PMI: payload missing indication

OCI: open connection indication

BDI-O: backward defect indication - overhead

BDI-P: backward defect indication - payload

FDI-O: forward defect indication - overhead

FDI-P: forward defect indication - payload

Page31

Non-a

ssocia

ted

overh

ead

OT

Sn

n

3 2

OC

h

1

General management communication

OM

Sn

FDI-O

FDI-P

OCI

BDI-O

BDI-P

PMI

FDI-P

FDI-O

BDI-O

BDI-P

PMI

TTI

OOS functions subject

to standardization. Bit

rate and format are not

standardized.

OPTICAL-LAYER FUNCTION

Page32

OT

Sn

BDI-O

BDI-P

PMI

TTI MI_TxTI

aPMI

RI_BDI-P

RI_BDI-O

Payload OTSn OH

dLOS_P

Payload and OH combined together APR control

OA, DCM

The OTS source function is used as an example.

OTN FRAME FORMATS (K = 1, 2, OR 3)

38

25

40

80

1

7

8

14

1

5

16

1

7

38

24

1

2

3

4

OPU k payload O

PU

k O

H

OPUk - optical channel payload unit

ODUk

OH

ODUk - Optical Channel Data Unit

Client signal

mapped in

OPUk payload

Client signal

OTUK

FEC

OTUk

OH

OTUk - Optical Channel Transport Unit

Alignment

Alignment

K:

1 - 2.5G

2 - 10G

3 - 40G

33

OTN ELECTRICAL OVERHEAD OVERVIEW

Page34

ODUk OH TCMACT: tandem connection monitoring

activation/deactivation control channel

TCMi: tandem connection monitoring i

FTFL: fault type and fault location reporting

channel

PM: path monitoring

EXP: experimental

GCC1/2: general communication channel

1/2

APS/PCC: automatic protection switching

coordination channel/protection

communication control channel

Alignment OH FAS: frame alignment signal

MFAS: multiframe alignment signal

OTUk OH SM: section monitoring

GCC0: general communication channel 0

RES: reserved for future international

standardization

OPUk OH PSI: payload structure identifier

JC: justification control

NJO: negative justification opportunity

RES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM3

TCM6 TCM5

TCM2 TCM1

TCM4

PM

TCM ACT

GCC1

FTFL RES JC

RES JC

NJO PSI GCC2 APS/PCC RES

EXP

FAS MFAS SM GCC0 RES JC RES

17

FRAME ALIGNMENT SIGNAL

Page35

Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6

1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8

OA1 OA1 OA1 OA2 OA2 OA2

RES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM3

TCM6 TCM5

TCM2 TCM1

TCM4

PM

TCM ACT

GCC1

FTFL RES JC

RES JC


EXP

FAS MFAS SM GCC0 RES JC RES

17

Frame alignment signal (FAS)

A six-byte OTUk-FAS signal is defined in row 1 and columns 1 to 6 of

the OTUk overhead.

OA1 is 0xF6 (1111 0110) and OA2 is 0x28 (0010 1000).

MULTIFRAME ALIGNMENT SIGNAL

Page36

MFAS OH byte

MF

AS

se

qu

en

ce

1 2 3 4 5 6 7 8

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1 0 0 0 0 0 1 0 0

.

.

.

.

.

.

1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

. .

Multiframe alignment signal (MFAS)

It is defined in row 1 and column 7.

The value of the MFAS byte is increased by

OTUk/ODUk frame and the MFAS byte provides a

maximum of 256 multiframes.

Individual OTUk/ODUk overhead signals may use this

central multiframe to lock their 2, 4, 8, 16, or 32

multiframes to the main frame.

RES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM3

TCM6 TCM5

TCM2 TCM1

TCM4

PM

TCM ACT

GCC1

FTFL RES JC

RES JC


EXP

FAS SM GCC0 RES JC RES

17

MFAS

OTUK SECTION MONITORING OVERHEAD

Page37

Trail trace identifier (TTI)

A one-byte overhead is defined to transport 64-byte TTI

signals.

The 64-byte TTI signal should be aligned with the OTUk

multiframe and transmitted four times per multiframe.

TTI structure:

16-byte SAPI: source access point identifier

16-byte DAPI: destination access point identifier

32-byte operator specified information

Operator specified

TTI BIP-8

BEI/BIAE BD

I

RES

1 2 3 4 5 6 7 8

1 2 3 IA

E

63

32

0

15

16

31

SAPI

DAPI

RES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM3

TCM6 TCM5

TCM2 TCM1

TCM4

PM

TCM ACT

GCC1

FTFL RES JC

RES JC


EXP

FAS GCC0 RES JC RES

17

MFAS SM


Bit interleaved parity-8 (BIP-8)

For section monitoring and a one-byte error detection code signals are defined.

This byte provides a bit interleaved parity-8 (BIP-8) code.

OTUk BIP-8 is computed over bits in the OPUk (columns 15 to 3824) area of OTUk

frame i, and inserted in the OTUk BIP-8 overhead location in OTUk frame i+2.

Page38

BIP8

OPUk

1 14 15 3824

Frame i

Frame i+1

Frame i+2


Backward error indication/backward incoming

alignment error (BEI/BIAE)

A four-bit BEI and BIAE signal is defined.

This signal is used to transmit in the upstream

direction the count of interleaved-bit blocks and

incoming alignment error (IAE) conditions.

During an IAE condition the code "1011" is inserted

into the BEI/BIAE field and the error count is ignored.

Otherwise the error count (0-8) is inserted into the

BEI/BIAE field.

Page39

Operator specified

TTI BIP-8

BEI/BIAE BD

I

RES

1 2 3 4 5 6 7 8

1 2 3 IA

E

63

32

0

15

16

31

SAPI

DAPI

RES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM3

TCM6 TCM5

TCM2 TCM1

TCM4

PM

TCM ACT

GCC1

FTFL RES JC

RES JC


EXP

FAS GCC0 RES JC RES MFAS SM


Backward defect indication (BDI)

A single-bit BDI signal is defined to transmit the

signal failure status detected by the section

termination sink function in the upstream direction.

BDI is set to "1" to indicate an OTUk backward

defect indication; otherwise, it is set to "0".

Page40

Operator specified

TTI BIP-8

BEI/BIAE BD

I

RES

1 2 3 4 5 6 7 8

1 2 3 IA

E

63

32

0

15

16

31

SAPI

DAPI

RES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM3

TCM6 TCM5

TCM2 TCM1

TCM4

PM

TCM ACT

GCC1

FTFL RES JC

RES JC


EXP

FAS GCC0 RES JC RES

17

MFAS SM


Incoming alignment error (IAE)

A single-bit IAE signal is defined to allow the S-

CMEP ingress point to inform its peer S-CMEP

egress point that an alignment error in the incoming

signal has been detected.

IAE is set to "1" to indicate a frame alignment error;

otherwise it is set to "0".

RES (reserved)

Two bits are reserved (RES) for future international

standardization. They are set to "00".

Page41

Operator specified

TTI BIP-8

BEI/BIAE BD

I

RES

1 2 3 4 5 6 7 8

1 2 3

IAE

63

32

0

15

16

31

SAPI

DAPI

RES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM3

TCM6 TCM5

TCM2 TCM1

TCM4

PM

TCM ACT

GCC1

FTFL RES JC

RES JC


EXP

FAS GCC0 RES JC RES

17

MFAS SM

OTUK GCC0 AND RES OVERHEAD

General communication channel (GCC0)

Two bytes are allocated in the OTUk overhead to support a general

communications channel between OTUk termination points.

A clear channel is located in row 1 and columns 11 and 12.

RES (reserved)

Two bytes of the OTUk overhead are reserved for future international

standardization.

They are located in row 1 and columns 13 and 14.

They are set to all “0”s.

Page42

RES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM3

TCM6 TCM5

TCM2 TCM1

TCM4

PM

TCM ACT

GCC1

FTFL RES JC

RES JC


EXP

FAS RES JC RES

17

MFAS SM GCC0

ODUK PATH MONITORING OVERHEAD

Page43

TTI / BIP-8 / BEI / BDI

For path monitoring, this overhead’s functions are

the same as those of the OTUk SM signal, except

that BEI signals do not support the BIAE function.

They are located in row 3 and columns 10 to 12.

Operator specified

TTI BIP-8

BEI BD

I

STAT

1 2 3 4 5 6 7 8

1 2 3

63

32

0

15 16

31

SAPI

DAPI

RES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM3

TCM6 TCM5

TCM2 TCM1

TCM4 TCM ACT

GCC1

FTFL RES JC

RES JC


EXP

FAS RES JC RES

17

MFAS SM GCC0

PM

ODUK PATH MONITORING OVERHEAD

Page44

Operator specified

TTI BIP-8

BEI BD

I

STAT

1 2 3 4 5 6 7 8

1 2 3

63

32

0

15 16

31

SAPI

DAPI

RES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM3

TCM6 TCM5

TCM2 TCM1

TCM4 TCM ACT

GCC1

FTFL RES JC

RES JC


EXP

FAS RES JC RES

17

MFAS SM GCC0

PM

Bit 678 Status

000 Reserved for future international standardization

001 Normal path signal




101 Maintenance signal: ODUk - LCK

110 Maintenance signal: ODUk - OCI

111 Maintenance signal: ODUk - AIS

Status (STAT)

For path monitoring, three bits are defined as status bits.

They indicate the presence of a maintenance signal.

ODUK TCM OVERHEAD

Page45

TTIi/BIP-8i/BEIi/BIAEi/BDIi

For each tandem connection monitoring field,

this overhead’s functions are the same as

those of OTUk SM signals.

Six fields of the ODUk TCM overhead are

defined in row 2 and columns 5 to 13, and

row 3 and columns 1 to 9 of the ODUk

overhead.

TTIi BIP-8i

BEIi/BIAEi BD

Ii

STATi

1 2 3 4 5 6 7 8

1 2 3

63

32

0

15 16

31

SAPI

DAPI

Operator specific

RES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM ACT

GCC1

FTFL RES JC

RES JC


EXP

FAS RES JC RES MFAS SM GCC0

PM TCM1 TCM2 TCM3

TCM6 TCM5 TCM4

ODUK TCM OVERHEAD

Page46

TTIi BIP-8i

BEIi/BIAEi BD

Ii

STATi

1 2 3 4 5 6 7 8

1 2 3

63

32

0

15 16

31

SAPI

DAPI

Operator specified

RES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM ACT

GCC1

FTFL RES JC

RES JC


EXP

FAS RES JC RES

17

MFAS SM GCC0

PM TCM1

Bit 678 Status

000 No source TC

001 In use without IAE

010 In use without IAE



101 Maintenance signal: ODUk -LCK

110 Maintenance signal: ODUk -OCI

111 Maintenance signal: ODUk -AIS

TCM2 TCM3

TCM6 TCM5 TCM4

STAT (status) For each tandem connection monitoring field, three

bits are defined as status bits.

They indicate the presence of a maintenance signal if there is an incoming alignment error at the source TC-CMEP, or if there is no source TC-

CMEP active.

NESTED AND CASCADED ODUK MONITORED

CONNECTIONS

Page47

A1 B1 C1 C2 B2 B3 B4 A2

A1 - A2

B1 - B2

C1 - C2

B3 - B4

TCM1 TCM1

TCM2

TCM1

TCM2

TCM3

TCM1

TCM2

TCM1 TCM1

TCM2

TCM1

TCM2

TCM3

TCM4

TCM5

TCM6

TCMi TCM OH field not in use TCMi TCM OH field in use

TCM2

TCM3

TCM4

TCM5

TCM6

TCM2

TCM3

TCM4

TCM5

TCM6

TCM3

TCM4

TCM5

TCM6

TCM3

TCM4

TCM5

TCM6

TCM3

TCM4

TCM5

TCM6

TCM4

TCM5

TCM6

OVERLAPPED ODUK MONITORED CONNECTIONS

Page48

A1 B1 C1 C2 B2 A2

A1 - A2

B1 - B2

C1 - C2

TCM1 TCM1

TCM2

TCM1

TCM2

TCM3

TCM1

TCM2

TCM1

TCMi TCM OH field not in use TCMi TCM OH field in use

TCM2

TCM3

TCM4

TCM5

TCM6

TCM2

TCM3

TCM4

TCM5

TCM6

TCM3

TCM4

TCM5

TCM6

TCM3

TCM4

TCM5

TCM6

TCM4

TCM5

TCM6

ODUK TCM ACT COORDINATION PROTOCOL

Page49

RES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM3

TCM6 TCM5

TCM2

TCM4 TCM ACT

GCC1

FTFL RES JC

RES JC

NJO PSI APS/PCC RES

EXP

FAS RES JC RES

17

MFAS SM GCC0

PM TCM1

GCC2

TCM activation/deactivation (TCMACT)

A one-byte TCM activation/deactivation field is located in row 2 and

column 4.

Its definition is to be defined in future.

ODUK GCC1/GCC2

Page50

RES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM3

TCM6 TCM5

TCM2

TCM4 TCM ACT

GCC1

FTFL RES JC

RES JC

NJO PSI APS/PCC RES

EXP

FAS RES JC RES

17

MFAS SM GCC0

PM TCM1

GCC2

General communication channel (GCC1/GCC2)

Two fields of the two bytes are allocated in the ODUk overhead to support

two general communication channels between any two NEs with access to

the ODUk frame structure (for example, at 3R regeneration points).

The bytes for GCC1 are located in row 4 and columns 1 and 2, and the

bytes for GCC2 are located in row 4 and columns 3 and 4 of the ODUk

overhead.

ODUK APS/PCC CHANNEL

Page51

RES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM3

TCM6 TCM5

TCM2

TCM4 TCM ACT

GCC1

FTFL RES JC

RES JC

NJO PSI RES

EXP

FAS RES JC RES

17

MFAS SM GCC0

PM TCM1

GCC2 APS/PCC

Automatic protection switching/protection communication control

(APS/PCC)

A four-byte ODUk-APS/PCC signal is defined in row 4 and columns 5 to 8 of the

ODUk overhead.

For linear protection schemes, bit assignments for these bytes and the bit oriented

protocol are given in ITU-T G.873.1. Bit assignment and byte oriented protocol for

ring protection schemes are to be defined in future.

A maximum of eight levels of nested APS/PCC signals may be present in this field.

ODUK FTFL CHANNEL

Fault Type & Fault Location (FTFL)

One byte is allocated in the ODUk overhead to transport a 256-byte FTFL

message.

The byte is located in row 2 and column 14 of the ODUk overhead.

The 256-byte FTFL message consists of two 128-byte fields. The forward

field is allocated in bytes 0 to 127 of the FTFL message. The backward field is

allocated in bytes 128 to 255 of the FTFL message.

Page52

RES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM3

TCM6 TCM5

TCM2

TCM4 TCM ACT

GCC1

RES JC

RES JC

NJO PSI APS/PCC RES

EXP

FAS RES JC RES

17

MFAS SM GCC0

PM TCM1

GCC2

FTFL

ODUK EXPERIMENTAL AND RESERVED OVERHEAD

Experimental (EXP)

Two bytes are allocated in the ODUk overhead for experimental use.

They are located in row 3 and columns 13 and 14 of the ODUk overhead.

There is no requirement for forwarding the EXP overhead over different (sub)networks.

RES

9 bytes are reserved in the ODUk overhead for future international standardization.

They are located in row 2 and columns 1 to 3, and row 4 and columns 9 to 14 of the

ODUk overhead.

They are set to all “0”s.

Page53

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM3

TCM6 TCM5

TCM2

TCM4 TCM ACT

GCC1

FTFL RES JC

RES JC

NJO PSI APS/PCC

FAS RES JC RES

17

MFAS SM GCC0

PM TCM1

GCC2

EXP

RES

RES

OPUK PAYLOAD STRUCTURE IDENTIFIER

Payload structure identifier (PSI)

One byte is allocated in the OPUk

overhead to transport a 256-byte payload

structure identifier (PSI) signal.

It is aligned with the ODUk multiframe.

PSI[0] contains a one-byte payload type.

PSI[1] to PSI[255] are mapping and

concatenation specific.

Page54

255

0

1

PT

Mapping

and concatenation

specific

RES

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

1

2

3

4

TCM3

TCM6 TCM5

TCM2

TCM4 TCM ACT

GCC1

RES JC

RES JC

NJO APS/PCC RES

EXP

FAS RES JC RES

17

MFAS SM GCC0

PM TCM1

GCC2

FTFL

PSI

PAYLOAD TYPE CODE POINTS

MSB 1234 LSB 1234 Hex Code Meaning

0000 0001 01 Experimental mapping

0000 0010 02 Asynchronous CBR mapping

0000 0011 03 Bit synchronous CBR mapping

0000 0100 04 ATM mapping

0000 0101 05 GFP mapping

0000 0110 06 Virtual Concatenated signal

0001 0000 10 Bit stream with octet timing mapping

0001 0001 11 Bit stream without octet timing mapping

0010 0000 20 ODU multiplex structure

0101 0101 55 Not available

0110 0110 66 Not available

1000 xxxx 80-8F Reserved codes for proprietary use

1111 1101 FD NULL test signal mapping

1111 1110 FE PRBS test signal mapping

1111 1111 FF Not available Page55

OPUK MAPPING SPECIFIC OVERHEAD

Justification control/negative justification opportunity/reserved

(JC/NJO/RES)

Seven bytes are reserved in the OPUk overhead for the mapping and concatenation

specific overhead.

These bytes are located in rows 1 to 3 and columns 15 and 16, and row 4 and

column 16.

255 bytes in the PSI are reserved for mapping and concatenation specific purposes.

Page56

RES

1

2

3

4

TCM3

TCM6 TCM5

TCM2

TCM4 TCM ACT

GCC1

RES JC

JC

APS/PCC RES

EXP

FAS RES JC RES MFAS SM GCC0

PM TCM1

GCC2 PSI

FTFL

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

RES

NJO

THANKS FOR BEING PATIENT

57

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