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        
 8     OTN Interfaces            
        8.1     Single-OTU (SOTU) interface          
        8.2     Multi-OTU (MOTU) interface          
        8.3     Single-OTU with management (SOTUm) interface      
        8.4      Multi-OTU with management (MOTUm) interface    
 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 frame structure    
       11.2     Scrambling       
       11.3     OTUCn 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 FlexE 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    
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   
      Page
       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 64B/66B 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   
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 and examples of ODUflex(GFP) clock generation    
       XI.1     Introduction      
       XI.2     Tributary slot sizes           
       XI.3     Example methods for ODUflex(GFP) clock generation              
Appendix XII – Terminology changes between ITU-T G.709 Edition 4 and Edition 5    
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
Bibliography