Doesnt matter whatever situation…CW Beeping / Switch Off ANNOUNCEMENT.
If you receive ANM You Generate CDR.If no dont.
This is what Normal Procedure evrywhere…But possible to generate CDRs for any kind of situation during calls.This is done for O&M Purpose.
The time in which CKT is occupied called Holding Time.Between IAM to RLC.
ANSWER Time ANM-REL.Holding Time alwys higher than ANSWER Time.
For Unanswered calls you can have min2/3 Mins of Holding Time.So your CKT is wasted during this time.