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 Overview of service environments of transport networks   
        6.1 Evolution of transport networks      
        6.2 Services environment of transport networks
7 Assessment indexes for the operational status of transport networks          
        7.1 Conventions for the concept of circuit operational state of a transport network        
        7.2     Service outage index (SOI)
        7.3 Service affected index        
8 Failure measuring approach of (O, A, P, R) quaternion     
Appendix I – Usage examples for assessment indexes     
        I.1      Examples for SOI and SAI applications    
        I.2      Example of early warning for circuit lines using SOI and SAI