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     Applications of OTN shared ring protection 
        6.1     Attributes of shared ring protection    
        6.2     Protection classifications          
        6.3     Applications considerations     
        6.4     Use of extra traffic      
 7     ODU SRP    
        7.1     Two and four-fibre ODU SRP types      
        7.2     Wrapping application of ODU SRP         
        7.3     Steering application of ODU shared ring protection      
 8     Interworking architectures 
        8.1     Single node interconnection   
        8.2     Dual node interconnection      
Annex A – Network objectives    
Appendix I – Examples of protection switching in an ODU SRP    
        I.1                   Unidirectional signal fail (span) in a four-fibre ring            
        I.2                   Unidirectional signal fail (ring)   
        I.3                   Bidirectional signal fail (ring)       
        I.4                   Unidirectional signal degrade (ring)        
        I.5                   Node failure      
        I.6                   Unidirectional SF-R pre-empting a unidirectional SD-S on non-adjacent spans    
        I.7                   Unidirectional SF-S pre-empting a unidirectional SF-R on adjacent spans – SF-S and SF-R detected at non-adjacent nodes    
        I.8                   Unidirectional SF-R pre-empting a unidirectional SD-S on adjacent spans              
        I.9                   Unidirectional SF-R coexisting with a unidirectional SF-R on non-adjacent spans
       I.10     Node failure on a ring with extra traffic capability         
       I.11     Unidirectional SF-S pre-empting a unidirectional SF-R on adjacent spans– SF-S and SF-R detected at adjacent nodes     
Appendix II – Generalized squelching logic    
       II.1     Squelching for unidirectional (and bidirectional) circuits              
       II.2     Squelching of multiply dropped and multiply sourced unidirectional circuits      
Appendix III – Ring configuration examples    
      III.1     2-fibre/2-lambda, 2-fibre/4-lambda and 4-fibre/4-lambda SRP-p Ring (22SRP-p, 24SRP‑p, 44SRP-p) configurations example    
      III.2     2 fibres/4 lambda, 4-fibre/4-lambda SRP-1 Ring (24SRP-1, 44SRP-1) configuration example    
      III.3     ODU SRP group protection example