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     General principles of the NGN functional architecture              
        6.1     General characteristics              
        6.2     Connectivity to the NGN           
 7     Overview of the NGN architecture    
        7.1     Transport stratum functions    
        7.2     Service stratum functions         
        7.3     End-user functions      
        7.4     Management functions             
        7.5     Identity management (IdM) functions  
 8     NGN concepts          
        8.1     Mobility levels in the NGN architecture
        8.2     NGN service architecture          
        8.3     Network topology hiding functions and NAPT traversal functions             
        8.4     Overload control         
        8.5     Charging and accounting functions (CAF)            
 9     Generalized NGN functional architecture       
        9.1     NGN functional architecture framework             
        9.2     NGN functional entities (FEs)   
        9.3     Functional entity descriptions  
        9.4     Reference points         
10     NGN components  
       10.1     NGN service-specific components        
       10.2     NGN transport-specific components   
       10.3     Management functions            
11     Security considerations       
Annex A – Differences between this edition and the 2006 edition of Recommendation ITU‑T Y.2012    
Annex B – Support of IPTV services    
        B.1      Overall functional mapping between NGN-based IPTV and NGN architectures    
        B.2     IMS-based IPTV functional architecture              
        B.3     Non-IMS-based IPTV architecture         
Appendix I – Examples of NGN network configurations    
        I.1                 Configurations and topology of the NGN
        I.2                 Relationship between the NGN and administrative domains            
        I.3                 Relationship between the NGN and service domains          
        I.4                 Enterprise role model     
        I.5                 Functional roles
Appendix II – Transport-stratum access network scenarios    
       II.1     Introduction   
       II.2     Scenario 1: Multi-layered transport stratum       
       II.3     Scenario 2: Access aggregation using layer-2     
       II.4     Scenario 3: Access aggregation using layer-3     
       II.5     Scenario 4: Multistage policy enforcement         
       II.6     Scenario 5: Partitioning into transport-layer traffic subdomains  
Appendix III – Instantiation of NGN reference points    
      III.1     Introduction   
      III.2     Scope
      III.3     Rationale to consider SNI          
      III.4     Instantiation of NGN reference points  
Appendix IV – Example illustrative deployment scenario for IdM in NGN    
Bibliography