1     Scope 
 2     References 
 3     Definitions  
        3.1     Terms defined elsewhere    
        3.2     Terms defined in this Recommendation       
 4     Abbreviations and acronyms        
 5     Architecture of the optical access network
        5.1     Network architecture         
        5.2     Reference configuration      
 6     Services, user‑network interface and service node interface          
        6.1     Services 
        6.2     User-network interface (UNI) and service node interface (SNI)     
 7     Bit rate
 8     Logical reach    
 9     Physical reach   
10     Differential fibre distance 
11     Maximum mean signal transfer delay        
12     Split ratio  
13     Service overlay
14     Protection on the PON section    
       14.1     Possible switching types    
       14.2     Possible duplex GPON configurations and characteristics  
       14.3     Requirements        
       14.4     Required information fields for OAM frame           
15     Security    
Appendix I – Examples of GPON services, architectures and service protocol stacks     
        I.1        Services, UNIs and SNIs 
        I.2        Typical system architectures         
        I.3        Service protocol stacks    
Appendix II – External access network backup     
Appendix III – Dual-parenting resilience