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           
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
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 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           
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