Table of Contents

 1     Scope 
 2     References 
 3     Definitions 
        3.1     Terms defined elsewhere 
        3.2     Terms defined in this Recommendation 
 4     Abbreviations and acronyms 
 5     Conventions 
 6     Optical transport network interface structure 
        6.1     Basic signal structure 
        6.2     Information structure for OTN interfaces 
 7     Multiplexing/mapping principles and bit rates 
        7.1     Mapping 
        7.2     Wavelength division multiplex 
        7.3     Bit rates and capacity 
        7.4     ODUk time‑division multiplex 
        7.5     Interconnection of Ethernet UNI and FlexE Group UNI in two administrative domains in the OTN    
 8     OTN Interfaces 
        8.1     Point-to-point interface, type I
        8.2     Point-to-point interface, type II
        8.3     Optical networking interface, type II
        8.4     Optical networking interface, type I
 9     Media Element 
10     OCh and OTSiA  
       10.1     OCh 
       10.2     Optical tributary signal assembly (OTSiA)
11     Optical transport unit (OTU)
       11.1     OTUk (k=0,1,2,3,4,4-SC) frame structure 
       11.2     Scrambling for OTUk (k=0,1,2,3,4)
       11.3     OTUCn frame structure 
       11.4     OTU25 and OTU50 frame structure 
12     Optical data unit (ODU)
       12.1     ODU frame structure 
       12.2     ODU bit rates and bit-rate tolerances 
13     Optical payload unit (OPU)
14     Overhead information carried over the OSC and OCC  
       14.1     OSC  
       14.2     OCC  
15     Overhead description 
       15.1     Types of overhead 
       15.2     Trail trace identifier and access point identifier definition 
       15.3     OTS-O description 
       15.4     OMS-O description 
       15.5     OCh-O and OTSiG-O description 
       15.6     OTU/ODU frame alignment OH description 
       15.7     OTU OH description 
       15.8     ODU OH description 
       15.9     OPU OH description 
16     Maintenance signals 
       16.1     OTS maintenance signals 
       16.2     OMS maintenance signals 
       16.3     OCh and OTiSA maintenance signals 
       16.4     OTU maintenance signals 
       16.5     ODU maintenance signals 
       16.6     Client maintenance signal
17     Mapping of client signals 
       17.1     OPU client signal fail (CSF)
       17.2     Mapping of CBR2G5, CBR10G, CBR10G3 and CBR40G signals into OPUk 
       17.3     Blank clause 
       17.4     Mapping of GFP frames into OPUk (k=0,1,2,3,4,flex)
       17.5     Mapping of test signal into OPU  
       17.6     Mapping of a non-specific client bit stream into OPUk 
       17.7     Mapping of other constant bit-rate signals with justification into OPUk             
       17.8     Mapping a 1000BASE-X and FC-1200 signal via timing transparent transcoding into OPUk    
       17.9     Mapping a supra-2.488 Gbit/s CBR signal into OPUflex using BMP 
      17.10     Mapping of packet client signals into OPUk 
      17.11     Mapping of 64B/66B encoded packet client signals into OPUflex using IMP 
      17.12     Mapping of FlexE aware signals into OPUflex 
      17.13     Mapping a 64B/66B PCS coded signal into OPUflex using BMP and 2-bit alignment of 66B code words    
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18     Blank clause 
19     Mapping ODUj signals into the ODTU signal and the ODTU into the OPUk tributary slots 
       19.1     OPUk tributary slot definition 
       19.2     ODTU definition 
       19.3     Multiplexing ODTU signals into the OPUk 
       19.4     OPUk multiplex overhead and ODTU justification overhead 
       19.5     Mapping ODUj into ODTUjk 
       19.6     Mapping of ODUj into ODTUk.ts 
20     Mapping ODUk signals into the ODTUCn signal and the ODTUCn into the OPUCn tributary slots    
       20.1     OPUCn tributary slot definition 
       20.2     ODTUCn definition 
       20.3     Multiplexing ODTUCn signals into the OPUCn 
       20.4     OPUCn multiplex overhead and ODTU justification overhead 
      20.5      Mapping ODUk into ODTUCn.ts 
Annex A – Forward error correction using 16-byte interleaved RS(255,239) codecs    
Annex B – Adapting 64B/66B encoded clients via transcoding into 513B code blocks    
        B.1     Transmission order 
        B.2     Client frame recovery 
        B.3     Transcoding from 66B blocks to 513B blocks 
        B.4     Link fault signalling 
Annex C – Adaptation of OTU3 and OTU4 over multichannel parallel interfaces    
Annex D – Generic mapping procedure principles    
        D.1     Basic principle 
        D.2     Applying GMP in OTN  
        D.3     Cm(t) encoding and decoding 
        D.4     SCnD(t) encoding and decoding 
Annex E – Adaptation of parallel 64B/66B encoded clients    
        E.1     Introduction 
        E.2     Clients signal format 
        E.3     Client frame recovery 
        E.4     Additions to Annex B transcoding for parallel 40GBASE-R clients 
Annex F – Improved robustness for mapping of 40GBASE-R into OPU3 using 1027B code blocks    
        F.1     Introduction 
        F.2     513B code block framing and flag bit protection 
        F.3     66B block sequence check 
Annex G – Mapping ODU0 into a low latency OTU0 (OTU0LL)    
        G.1     Introduction 
        G.2     Optical transport unit 0 low latency (OTU0LL)
Annex H – OTUCn sub rates (OTUCn-M)    
        H.1     Introduction 
        H.2     OTUCn-M frame format 
Annex I    
Annex J – Recovery of 64B/66B encoded clients from parallel 256B/257B interfaces    
Annex K – Transporting 200GbE and 400GbE am_sf<2:0> information through a single optical link between two Ethernet/OTN transponder entities in the OTN    
        K.1     Introduction 
        K.2     Client Degrade Indication (CDI) overhead 
Annex L – OTU25u and OTU50u interfaces    
        L.1     Introduction 
        L.2     Bit rates 
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)    
Appendix II – Examples of functionally standardized OTU frame structures    
Appendix III – Example of ODUk multiplexing    
Appendix IV – Blank appendix    
Appendix V – ODUk multiplex structure identifier (MSI) examples    
Appendix VI – Parallel logic implementation of the CRC-9, CRC-8, CRC-5 and CRC-6    
Appendix VII – OTL4.10 structure    
Appendix VIII – CPRI into ODU mapping    
Appendix IX – Overview of CBR clients into OPU mapping types    
Appendix X – Overview of ODUj into OPUk mapping types    
Appendix XI – Derivation of recommended ODUflex(GFP) bit-rates based on n × ODUk.ts clock and examples of ODUflex(GFP,n,k) clock generation    
       XI.1     Introduction 
       XI.2     Tributary slot sizes 
       XI.3     Example methods for ODUflex(GFP,n,k) clock generation 
Appendix XII – Terminology changes between ITU-T G.709 Edition 4, Edition 5 and Edition 6    
Appendix XIII – OTUCn sub rates (OTUCn-M) Applications    
     XIII.1     Introduction 
     XIII.2     OTUCn-M frame format and rates 
     XIII.3     OTUCn-M fault condition 
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Appendix XIV – Examples of interconnection of Ethernet UNI and FlexE Group UNI  in two administrative domains in the OTN for the case that these UNIs deploy different mapping methods    
Appendix XV – Examples of ODUflex(GFP) and ODUflex(IMP) clock generation methods    
Appendix XVI – Implications of OTSiG (de)modulator processes and OCh|OTSiG overhead trail termination functions being located in adjacent network elements    
      XVI.1     Introduction 
      XVI.2     Black link deployment without co-location of OTSiG (de)modulator and OTSiG‑O_TT/OCh-O_TT function    
      XVI.3     Failure correlation for black link deployment without colocation of OTSiG (de)modulator and OTSiG-O_TT/OCh-O_TT function    
Bibliography