CONTENTS

 1     Scope 
 2     References 
 3     Terms and definitions       
 4     Abbreviations   
 5     Conventions     
 6     Optical transport network interface structure        
        6.1     Basic signal structure          
        6.2     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         
        7.4     ODUk Time‑Division Multiplex      
 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)   
        8.2     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
       15.2     Trail trace identifier and access point identifier definition     
       15.3     OTS OH description        
       15.4     OMS OH description       
       15.5     OCh OH description        
       15.6     OTUk/ODUk frame alignment OH description      
       15.7     OTUk OH description      
       15.8     ODUk OH description     
       15.9     OPUk OH description      
16     Maintenance signals        
       16.1     OTS maintenance signals  
       16.2     OMS maintenance signals 
       16.3     OCh maintenance signals  
       16.4     OTUk maintenance signals
       16.5     ODUk maintenance signals           
       16.6     Client maintenance signal   
17     Mapping of client signals 
       17.1     Mapping of CBR2G5, CBR10G and CBR40G signals (e.g., STM-16/64/256) into OPUk     
       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  
       17.5     Mapping of a non-specific client bit stream into OPUk       
       17.6     Mapping of other constant bit-rate signals with justification into OPUk       
18     Concatenation 
       18.1     Virtual concatenation of OPUk     
       18.2     Mapping of client signals   
       18.3     LCAS for virtual concatenation     
19     Mapping ODUk signals into the ODTUjk signal  
       19.1     OPUk Tributary Slot definition      
       19.2     ODTUjk definition
       19.3     Multiplexing ODTUjk signals into the OPUk         
       19.4     OPUk Multiplex Overhead           
       19.5     Mapping ODUj into ODTUjk       
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, 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 – Example of fixed stuff in OPUk with multiplex of lower‑order ODUk signals    
Appendix V – Range of stuff ratios for asynchronous multiplexing of ODUj into ODUk (k > j)