1 Ineffective outgoing call
1.1 Non-return of the call-confirmation and/or proceed-to-select
signal(s)
1.2 Slow or incomplete selection
1.3 No response after selection
1.4 Ineffective attempts followed by service signals
1.5 Ineffective calls characterized by a clearing signal without a
preceding service signal
1.6 Reception of an answerback
1.7 Possible terminal configuration
2
Ineffective incoming calls
2.1 False calls
3
Incidents following call set-up
3.1 Idle circuit without clearing signal
3.2 No clear-confirmation