1     Scope        
 2     References             
 3     Definitions
        3.1     Terms defined elsewhere      
        3.2     Terms defined in this Recommendation          
 4     Abbreviations         
 5     Conventions           
        5.1     Representation of octets        
 6     Introduction           
 7     Ring protection characteristics        
        7.1     Monitoring methods and conditions   
        7.2     Ethernet traffic and bandwidth consideration 
        7.3     Ethernet ring protection switching performance         
 8     Ring protection conditions and commands  
 9     Ring protection architectures          
        9.1     Revertive and non-revertive switching            
        9.2     Protection switching triggers 
        9.3     Protection switching models on a single Ethernet ring
        9.4     Traffic channel blocking        
        9.5     R-APS channel blocking          
        9.6     FDB flush      
        9.7     Ethernet ring protection switching models for interconnection
10     Protection control protocol             
       10.1     Principles of operations        
       10.2     Protection switching behaviour         
       10.3     R-APS format           
       10.4     Failure of protocol defect     
Appendix I – Ring protection network objectives    
Appendix II – Ethernet ring network objectives    
Appendix III – Ring protection scenarios     
Appendix IV – Considerations for the different timers    
       IV.1     State machine use of timers  
       IV.2     Guard timer use to block outdated R-APS messages    
Appendix V – Interconnected rings example    
        V.1     Configuration for interconnected rings           
        V.2     Topology examples for interconnected Ethernet rings
Appendix VI – Protection switching for multiple ERP instances    
       VI.1     Multiple ERP instances          
       VI.2     Applying protection mechanisms to multiple ERP instances     
       VI.3     Protection switching model for multiple ERP instances            
       VI.4     Multiple instances of interconnected rings     
Appendix VII – Guidelines for the configuration of VIDs and Ring-IDs of R-APS channels    
      VII.1     Sub-ring with R-APS virtual channel   
      VII.2     Example 3: Sub-ring without R-APS virtual channel model; each R-APS channel with different VIDs    
      VII.3     Example 4: Co-existence on an Ethernet ring of Ethernet ring nodes which support this Recommendation (v2) and the previous version (v1) of this Recommendation    
Appendix VIII – Flush optimization    
     VIII.1     Flushing FDB consideration   
     VIII.2     Scenarios of unnecessary FDB flushing            
     VIII.3     Example of FDB flush optimization     
     VIII.4     Additional definition for ERP control process model and state machine             
     VIII.5     DNF status   
Appendix IX – Guidelines for management procedures    
       IX.1     An example procedure for removing an Ethernet ring node     
       IX.2     Management procedures to exit the FS state in case of failure of an Ethernet ring node under an FS condition    
       IX.3     Replacing a v1 Ethernet ring node with a v2 Ethernet ring node           
Appendix X – Minimizing segmentation in interconnected rings    
        X.1     Characterization of the segmentation issue    
        X.2     Class of double faults addressed         
        X.3     Procedure for minimization of segmentation  
Appendix XI – End-to-end service resilience    
       XI.1     Generic end-to-end service resilience
       XI.2     Layering ITU-T G.8031 protection over ITU-T G.8032   
       XI.3     End-to-end service that traverses interconnected rings