1     Definitions
        1.1     essential information (of internal automatic observations)
        1.2     supplementary information (of internal automatic observations)
        1.3     Answer Seizure Ratio (ASR)
        1.4     Answer Bid Ratio (ABR)
        1.5     Network Effectiveness Ratio (NER)
 2     Merits of internal automatic observations
 3     Time of observations
 4     Exchange of the results of observations
 5     Classes of calls
 6     Destination analysis from service observation data
 7     Details about supplementary information for Signalling System No. 5
        7.1     Signalling faults
        7.2     Ineffective calls associated with the calling subscriber
        7.3     Ineffective calls associated with the called subscriber
        7.4     Network
 8     Equipment impact
Annex A - Cause value categorization