CONTENTS

 1     Scope
 2     References
 3     Terms and definitions
 4     Abbreviations
 5     Conventions
 6     Optical transport network interface structure
        6.1     Basic signal structure
                  6.1.1     OCh substructure
                  6.1.2     Full functionality OTM‑n.m (n ≥ 1) structure
                  6.1.3     Reduced functionality OTM‑nr.m and OTM‑0.m structure
        6.2     Information structure for the OTN interfaces
 7     Multiplexing/mapping principles and bit rates
        7.1     Mapping
        7.2     Wavelength division multiplex
        7.3     Bit rates and capacity
 8     Optical transport module (OTM‑n.m, OTM‑nr.m, OTM‑0.m)
        8.1     OTM with reduced functionality (OTM‑0.m, OTM‑nr.m)
                  8.1.1     OTM‑0.m
                  8.1.2     OTM‑16r.m
        8.2     OTM with full functionality (OTM‑n.m)
 9     Physical specification of the ONNI
        9.1     OTM‑0.m
        9.2     OTM‑16r.m
        9.3     OTM‑n.m
10     Optical channel (OCh)
       10.1     OCh with full functionality (OCh)
       10.2     OCh with reduced functionality (OChr)
11     Optical channel transport unit (OTU)
       11.1     OTUk frame structure
       11.2     Scrambling
12     Optical channel data unit (ODUk)
       12.1     ODUk frame structure
13     Optical channel payload unit (OPUk)
14     OTM overhead signal (OOS)
15     Overhead description
       15.1     Types of overhead
                 15.1.1     Optical channel payload unit overhead (OPUk OH)
                 15.1.2     Optical channel data unit overhead (ODUk OH)
                 15.1.3     Optical channel transport unit overhead (OTUk OH)
                 15.1.4     Optical channel non-associated overhead (OCh OH)
                 15.1.5     Optical multiplex section overhead (OMS OH)
                 15.1.6     Optical transmission section overhead (OTS OH)
                 15.1.7     General management communications overhead (COMMS OH)
       15.2     Trail trace identifier and access point identifier definition
       15.3     OTS OH description
                 15.3.1     OTS trail trace identifier (TTI)
                 15.3.2     OTS backward defect indication – Payload (BDI-P)
                 15.3.3     OTS backward defect indication – Overhead (BDI-O)
                 15.3.4     OTS payload missing indication (PMI)
       15.4     OMS OH description
                 15.4.1     OMS forward defect indication – Payload (FDI-P)
                 15.4.2     OMS forward defect indication – Overhead (FDI-O)
                 15.4.3     OMS backward defect indication – Payload (BDI-P)
                 15.4.4     OMS backward defect indication – Overhead (BDI-O)
                 15.4.5     OMS payload missing indication (PMI)
       15.5     OCh OH description
                 15.5.1     OCh forward defect indication – Payload (FDI-P)
                 15.5.2     OCh forward defect indication – Overhead (FDI-O)
                 15.5.3     OCh open connection indication (OCI)
       15.6     OTUk/ODUk frame alignment OH description
                 15.6.1     OTUk/ODUk frame alignment overhead location
                 15.6.2     OTUk/ODUk frame alignment overhead definition
       15.7     OTUk OH description
                 15.7.1     OTUk overhead location
                 15.7.2     OTUk overhead definition
                 15.7.3     OTUkV overhead
       15.8     ODUk OH description
                 15.8.1     ODUk OH location
                 15.8.2     ODUk OH definition
       15.9     OPUk OH description
                 15.9.1     OPUk OH location
                 15.9.2     OPUk OH definition
16     Maintenance signals
       16.1     OTS maintenance signals
                 16.1.1     OTS payload missing indication (OTS-PMI)
       16.2     OMS maintenance signals
                 16.2.1     OMS forward defect indication – Payload (OMS-FDI-P)
                 16.2.2     OMS forward defect indication – Overhead (OMS-FDI-O)
                 16.2.3     OMS payload missing indication (OMS-PMI)
       16.3     OCh maintenance signals
                 16.3.1     OCh forward defect indication – Payload (OCh-FDI-P)
                 16.3.2     OCh forward defect indication – Overhead (OCh-FDI-O)
                 16.3.3     OCh open connection indication (OCh-OCI)
       16.4     OTUk maintenance signals
                 16.4.1     OTUk alarm indication signal (OTUk-AIS)
       16.5     ODUk maintenance signals
                 16.5.1     ODUk alarm indication signal (ODUk-AIS)
                 16.5.2     ODUk open connection indication (ODUk-OCI)
                 16.5.3     ODUk locked (ODUk-LCK)
       16.6     Client maintenance signal
                 16.6.1     Generic AIS for constant bit rate signals
17     Mapping of client signals
       17.1     Mapping of CBR2G5, CBR10G and CBR40G signals (e.g. STM-16/64/256) into OPUk
                 17.1.1     Mapping a CBR2G5 signal (e.g. STM-16) into OPU1
                 17.1.2     Mapping a CBR10G signal (e.g. STM-64) into OPU2
                 17.1.3     Mapping a CBR40G signal (e.g. STM-256) into OPU3
       17.2     Mapping of ATM cell stream into OPUk
       17.3     Mapping of GFP frames into OPUk
       17.4     Mapping of test signal into OPUk
                 17.4.1     Mapping of a NULL client into OPUk
                 17.4.2     Mapping of PRBS test signal into OPUk
       17.5     Mapping of a non-specific client bit stream into OPUk
                 17.5.1     Mapping bit stream with octet timing into OPUk
                 17.5.2     Mapping bit stream without octet timing into OPUk
       17.6     Mapping of other constant bit-rate signals with justification into OPUk
Annex A – Forward error correction using 16-byte interleaved RS(255,239) codecs
Appendix I – Range of stuff ratios for asynchronous mappings of CBR2G5, CBR10G, and CBR40G clients with ±20 ppm bit-rate tolerance into OPUk
Appendix II – Examples of functionally standardized OTU frame structures