ITU-T.G709.pdf

【核心代码】

Table of Contents
Page
1 Scope.............................................................................................................................9
2 References.....................................................................................................................9
3 Definitions ....................................................................................................................11
3.1 Terms defined elsewhere................................................................................11
3.2 Terms defined in this Recommendation.........................................................12
4 Abbreviations and acronyms ........................................................................................12
5 Conventions..................................................................................................................17
6 Optical transport network interface structure ...............................................................18
6.1 Basic signal structure......................................................................................18
6.1.1 OTN digital structure......................................................................................18
6.1.2 OTN optical structure .....................................................................................19
6.2 Information structure for OTN interfaces.......................................................20
7 Multiplexing/mapping principles and bit rates.............................................................24
7.1 Mapping..........................................................................................................26
7.2 Wavelength division multiplex.......................................................................26
7.3 Bit rates and capacity......................................................................................26
7.4 ODUk time-division multiplex.......................................................................31
8 OTN Interfaces .............................................................................................................40
8.1 Single-OTU (SOTU) interface .......................................................................40
8.2 Multi-OTU (MOTU) interface .......................................................................40
8.3 Single-OTU with management (SOTUm) interface.......................................41
8.4 Multi-OTU with management (MOTUm) interface......................................41
9 Media Element..............................................................................................................41
10 OCh and OTSiA ...........................................................................................................41
10.1 OCh.................................................................................................................41
10.2 Optical tributary signal assembly (OTSiA)....................................................42
11 Optical transport unit (OTU) ........................................................................................42
11.1 OTUk frame structure.....................................................................................42
11.2 Scrambling......................................................................................................43
11.3 OTUCn frame structure..................................................................................44
12 Optical data unit (ODU) ...............................................................................................44
12.1 ODU frame structure ......................................................................................44
12.2 ODU bit rates and bit-rate tolerances.............................................................45
12.2.1 ODU0, ODU1, ODU2, ODU3, ODU4, ODUCn ...........................................45
12.2.2 ODU2e............................................................................................................46
Rec. ITU-T G.709/Y.1331 (06/2016) – Prepublished version 3
12.2.3 ODUflex for CBR client signals.....................................................................46
12.2.4 ODUflex for PRBS and Null test signals.......................................................46
12.2.5 ODUflex for GFP-F mapped packet client signals.........................................46
12.2.6 ODUflex for IMP mapped client signals........................................................47
13 Optical payload unit (OPU)..........................................................................................48
14 Overhead information carried over the OSC and OCC................................................49
15 Overhead description ....................................................................................................49
15.1 Types of overhead ..........................................................................................53
15.1.1 Optical payload unit overhead (OPU OH) .....................................................53
15.1.2 Optical data unit overhead (ODU OH)...........................................................53
15.1.3 Optical transport unit overhead (OTU OH)....................................................54
15.1.4 OCh-O ............................................................................................................54
15.1.5 OMS-O ...........................................................................................................54
15.1.6 OTS-O ............................................................................................................54
15.1.7 General management communications overhead (COMMS OH)..................54
15.1.8 OTSiG-O ........................................................................................................54
15.2 Trail trace identifier and access point identifier definition ............................55
15.3 OTS-O description..........................................................................................56
15.3.1 OTS trail trace identifier (TTI).......................................................................56
15.3.2 OTS backward defect indication – Payload (BDI-P) .....................................56
15.3.3 OTS backward defect indication – Overhead (BDI-O)..................................57
15.3.4 OTS payload missing indication (PMI)..........................................................57
15.4 OMS-O description ........................................................................................57
15.4.1 OMS forward defect indication – Payload (FDI-P) .......................................57
15.4.2 OMS forward defect indication – Overhead (FDI-O)....................................57
15.4.3 OMS backward defect indication – Payload (BDI-P)....................................57
15.4.4 OMS backward defect indication – Overhead (BDI-O).................................57
15.4.5 OMS payload missing indication (PMI).........................................................57
15.4.6 OMS multiplex structure identifier (MSI)......................................................57
15.5 OCh-O and OTSiG-O description..................................................................58
15.5.1 OCh and OTSiA forward defect indication – Payload (FDI-P) .....................58
15.5.2 OCh and OTSiA forward defect indication – Overhead (FDI-O)..................58
15.5.3 OCh and OTSiA open connection indication (OCI) ......................................58
15.5.4 OCh-O transport over SOTUm interface .......................................................58
15.5.5 OTSiA backward defect indication – Payload (BDI-P) .................................59
15.5.6 OTSiA backward defect indication – Overhead (BDI-O)..............................59
15.5.7 OTSiA trail trace identifier (TTI)...................................................................59
15.5.8 OTSiG transmitter structure identifier (TSI)..................................................59
15.6 OTU/ODU frame alignment OH description .................................................59
Rec. ITU-T G.709/Y.1331 (06/2016) – Prepublished version 4
15.6.1 OTU/ODU frame alignment overhead location .............................................59
15.6.2 OTU/ODU frame alignment overhead definition...........................................59
15.7 OTU OH description ......................................................................................60
15.7.1 OTU overhead location ..................................................................................60
15.7.2 OTU overhead definition................................................................................61
15.7.3 OTUkV overhead ...........................................................................................67
15.8 ODU OH description......................................................................................67
15.8.1 ODU OH location...........................................................................................67
15.8.2 ODU OH definition ........................................................................................68
15.9 OPU OH description.......................................................................................81
15.9.1 OPU OH location ...........................................................................................81
15.9.2 OPU OH definition.........................................................................................81
16 Maintenance signals......................................................................................................84
16.1 OTS maintenance signals ...............................................................................84
16.1.1 OTS payload missing indication (OTS-PMI).................................................84
16.2 OMS maintenance signals..............................................................................84
16.2.1 OMS forward defect indication – Payload (OMS-FDI-P) .............................84
16.2.2 OMS forward defect indication – Overhead (OMS-FDI-O) ..........................84
16.2.3 OMS payload missing indication (OMS-PMI)...............................................84
16.3 OCh and OTiSA maintenance signals............................................................85
16.3.1 OCh and OTiSA forward defect indication – Payload (OCh-FDI-P,
OTSiA-FDI-P)................................................................................................85
16.3.2 OCh and OTiSA forward defect indication – Overhead (OCh-FDI-O,
OTSiA-FDI-O) ...............................................................................................85
16.3.3 OCh and OTiSA open connection indication (OCh-OCI, OTSiA-OCI)........85
16.4 OTU maintenance signals...............................................................................85
16.4.1 OTUk alarm indication signal (OTUk-AIS)...................................................85
16.4.2 OTUCn alarm indication signal (OTUCn-AIS) .............................................85
16.5 ODU maintenance signals..............................................................................86
16.5.1 ODU alarm indication signal (ODU-AIS)......................................................86
16.5.2 ODUk open connection indication (ODUk-OCI)...........................................87
16.5.3 ODU locked (ODU-LCK)..............................................................................87
16.6 Client maintenance signal...............................................................................88
16.6.1 Generic AIS for constant bit rate signals........................................................88
17 Mapping of client signals..............................................................................................88
17.1 OPU client signal fail (CSF)...........................................................................89
17.2 Mapping of CBR2G5, CBR10G, CBR10G3 and CBR40G signals into
OPUk ..............................................................................................................89
17.2.1 Mapping a CBR2G5 signal (e.g., STM-16, CMGPON_D/CMGPON_U2)
into OPU1.......................................................................................................92
Rec. ITU-T G.709/Y.1331 (06/2016) – Prepublished version 5
17.2.2 Mapping a CBR10G signal (e.g., STM-64,
CMXGPON_D/CMXGPON_U2) into OPU2................................................92
17.2.3 Mapping a CBR40G signal (e.g., STM-256) into OPU3 ...............................92
17.2.4 Mapping a CBR10G3 signal (e.g., 10GBASE-R) into OPU2e......................93
17.3 Blank clause....................................................................................................93
17.4 Mapping of GFP frames into OPUk (k=0,1,2,3,4,flex)..................................93
17.4.1 Mapping of GFP frames into an extended OPU2 payload area .....................94
17.5 Mapping of test signal into OPU....................................................................95
17.5.1 Mapping of a NULL client into OPU.............................................................95
17.5.2 Mapping of PRBS test signal into OPU .........................................................96
17.6 Mapping of a non-specific client bit stream into OPUk.................................96
17.6.1 Mapping bit stream with octet timing into OPUk ..........................................97
17.6.2 Mapping bit stream without octet timing into OPUk .....................................97
17.7 Mapping of other constant bit-rate signals with justification into OPUk.......97
17.7.1 Mapping a sub-1.238 Gbit/s CBR client signal into OPU0............................99
17.7.1.2 FC-100............................................................................................................101
17.7.1.3 SBCON/ESCON.............................................................................................101
17.7.2 Mapping a supra-1.238 to sub-2.488 Gbit/s CBR client signal into OPU1 ...101
17.7.3 Mapping CBR client signals into OPU2 ........................................................103
17.7.4 Mapping CBR client signals into OPU3 ........................................................104
17.7.5 Mapping CBR client signals into OPU4 ........................................................106
17.8 Mapping a 1000BASE-X and FC-1200 signal via timing transparent
transcoding into OPUk ...................................................................................108
17.8.1 Mapping a 1000BASE-X signal into OPU0...................................................108
17.8.2 Mapping an FC-1200 signal into OPU2e .......................................................108
17.9 Mapping a supra-2.488 Gbit/s CBR signal into OPUflex using BMP...........111
17.9.1 FC-400 and FC-800........................................................................................113
17.9.2 FC-1600..........................................................................................................113
17.10 Mapping of packet client signals into OPUk..................................................114
17.11 Mapping of FlexE Client signals into OPUflex using IMP............................114
17.12 Mapping of FlexE Aware signals into OPUflex.............................................115
18 Blank clause..................................................................................................................119
19 Mapping ODUj signals into the ODTU signal and the ODTU into the OPUk
tributary slots................................................................................................................120
19.1 OPUk tributary slot definition ........................................................................120
19.1.1 OPU2 tributary slot allocation........................................................................120
19.1.2 OPU3 tributary slot allocation........................................................................122
19.1.3 OPU1 tributary slot allocation........................................................................124
19.1.4 OPU4 tributary slot allocation........................................................................125
19.2 ODTU definition ............................................................................................128
Rec. ITU-T G.709/Y.1331 (06/2016) – Prepublished version 6
19.3 Multiplexing ODTU signals into the OPUk...................................................130
19.3.1 ODTU12 mapping into one OPU2 tributary slot ...........................................131
19.3.2 ODTU13 mapping into one OPU3 tributary slot ...........................................132
19.3.3 ODTU23 mapping into four OPU3 tributary slots.........................................133
19.3.4 ODTU01 mapping into one OPU1 1.25G tributary slot.................................135
19.3.5 ODTU2.ts mapping into ts OPU2 1.25G tributary slots ................................135
19.3.6 ODTU3.ts mapping into ts OPU3 1.25G tributary slots ................................136
19.3.7 ODTU4.ts mapping into ts OPU4 1.25G tributary slots ................................137
19.4 OPUk multiplex overhead and ODTU justification overhead .......................139
19.4.1 OPUk multiplex structure identifier (MSI) ....................................................143
19.4.2 OPUk payload structure identifier reserved overhead (RES).........................148
19.4.3 OPUk multiplex justification overhead (JOH)...............................................148
19.4.4 OPU multiframe identifier overhead (OMFI) ................................................149
19.5 Mapping ODUj into ODTUjk ........................................................................149
19.5.1 Mapping ODU1 into ODTU12.......................................................................151
19.5.2 Mapping ODU1 into ODTU13.......................................................................153
19.5.3 Mapping ODU2 into ODTU23.......................................................................155
19.5.4 Mapping ODU0 into ODTU01.......................................................................158
19.6 Mapping of ODUj into ODTUk.ts..................................................................158
19.6.1 Mapping ODUj into ODTU2.M.....................................................................160
19.6.2 Mapping ODUj into ODTU3.M.....................................................................160
19.6.3 Mapping ODUj into ODTU4.M.....................................................................162
20 Mapping ODUk signals into the ODTUCn signal and the ODTUCn into the OPUCn
tributary slots................................................................................................................162
20.1 OPUCn tributary slot definition .....................................................................163
20.1.1 OPUCn tributary slot allocation .....................................................................163
20.2 ODTUCn definition........................................................................................167
20.3 Multiplexing ODTUCn signals into the OPUCn............................................168
20.3.1 ODTUCn.ts mapping into ts OPUCn 5G tributary slots................................168
20.4 OPUCn multiplex overhead and ODTU justification overhead.....................169
20.4.1 OPUCn multiplex structure identifier (MSI)..................................................170
20.4.2 OPUCn payload structure identifier reserved overhead (RES)......................171
20.4.3 OPUCn multiplex justification overhead (JOH) ............................................171
20.4.4 OPUCn multiframe identifier overhead (OMFI)............................................172
20.5 Mapping ODUk into ODTUCn.ts ..................................................................173
20.5.1 Mapping ODUk into ODTUCn.M .................................................................175
Annex A Forward error correction using 16-byte interleaved RS(255,239) codecs ..............176
Annex B Adapting 64B/66B encoded clients via transcoding into 513B code blocks...........178
B.1 Transmission order.........................................................................................178
Rec. ITU-T G.709/Y.1331 (06/2016) – Prepublished version 7
B.2 Client frame recovery .....................................................................................178
B.3 Transcoding from 66B blocks to 513B blocks...............................................179
B.3.1 Errors detected before 512B/513B encoder ...................................................183
B.3.2 Errors detected by 512B/513B decoder..........................................................184
B.4 Link fault signalling .......................................................................................184
Annex C Adaptation of OTU3 and OTU4 over multichannel parallel interfaces ..................185
Annex D Generic mapping procedure principles....................................................................188
D.1 Basic principle ................................................................................................188
D.2 Applying GMP in OTN..................................................................................191
D.3 Cm(t) encoding and decoding .........................................................................195
D.4 CnD(t) encoding and decoding......................................................................201
D.4.1 CnD(t) encoding and decoding for OPUk .....................................................201
D.4.2 CnD(t) encoding and decoding for OPUCn...................................................202
Annex E Adaptation of parallel 64B/66B encoded clients.....................................................203
E.1 Introduction ....................................................................................................203
E.2 Clients signal format.......................................................................................203
E.3 Client frame recovery .....................................................................................203
E.3.1 40GBASE-R client frame recovery................................................................205
E.3.2 100GBASE-R client frame recovery..............................................................205
E.4 Additions to Annex B transcoding for parallel 64B/66B clients....................206
E.4.1 BIP-8 transparency .........................................................................................207
E.4.2 Errors detected by mapper..............................................................................208
E.4.3 Errors detected by de-mapper.........................................................................208
Annex F Improved robustness for mapping of 40GBASE-R into OPU3 using 1027B code
blocks............................................................................................................................209
F.1 Introduction ....................................................................................................209
F.2 513B code block framing and flag bit protection...........................................209
F.3 66B block sequence check..............................................................................210
F.3.1 State diagram conventions..............................................................................210
F.3.2 State variables.................................................................................................211
F.3.3 State diagrams ................................................................................................212
Annex G Mapping ODU0 into a low latency OTU0 (OTU0LL) ...........................................215
G.1 Introduction ....................................................................................................215
G.2 Optical transport unit 0 low latency (OTU0LL).............................................215
G.2.1 OTUk frame structure.....................................................................................215
G.2.2 Scrambling......................................................................................................216
Annex H OTUCn sub rates (OTUCn-M)................................................................................218
H.1 Introduction ....................................................................................................218
Rec. ITU-T G.709/Y.1331 (06/2016) – Prepublished version 8
H.2 OTUCn-M frame format ................................................................................218
Appendix I Range of stuff ratios for asynchronous mappings of CBR2G5, CBR10G, and
CBR40G clients with 20 ppm bit-rate tolerance into OPUk, and for asynchronous
multiplexing of ODUj into ODUk (k > j).....................................................................219
Appendix II Examples of functionally standardized OTU frame structures ..........................225
Appendix III Example of ODUk multiplexing .......................................................................228
Appendix IV Blank appendix .................................................................................................230
Appendix V ODUk multiplex structure identifier (MSI) examples .......................................231
Appendix VI Parallel logic implementation of the CRC-9, CRC-8, CRC-6 and CRC-5.......233
Appendix VII OTL4.10 structure............................................................................................236
Appendix VIII CPRI into ODU mapping ...............................................................................237
Appendix IX Overview of CBR clients into OPU mapping types .........................................238
Appendix X Overview of ODUj into OPUk mapping types ..................................................240
Appendix XI Derivation of recommended ODUflex(GFP) bit-rates and examples of
ODUflex(GFP) clock generation..................................................................................242
XI.1 Introduction ....................................................................................................242
XI.2 Tributary slot sizes .........................................................................................242
XI.3 Example methods for ODUflex(GFP) clock generation ................................245
XI.3.1 Generating ODUflex(GFP) clock from OPUk clock ....................................245
XI.3.2 Generating ODUflex(GFP) clock from system clock ....................................246
Appendix XII Terminology changes between G.709 Edition 4 and Edition 5.......................247
Appendix XIII OTUCn sub rates (OTUCn-M) Applications.................................................249
XIII.1 Introduction ....................................................................................................249
XIII.2 OTUCn-M frame format and rates.................................................................249
XIII.3 OTUCn-M fault condition..............................................................................250
Bibliography.............................................................................................................................251