Call detail service is provided using a trigger that only activates after
the disposition of a telephone call is known, for example, a T-Busy
and/or a T_NoAnswer. When a telephone call encounters the T-Busy or
T_NoAnswer trigger a terminating central office switch attempts to
complete the call. If the call is not completed because it is busy or not
answered, the information related to the call is sent to a service
control point. The service control point creates a call information
record. The call information record is sent to a service management
system that used the call information record to create a call detail
report. Using the T_Busy and/or T_NoAnswer triggers eliminates the need
to collect data for every telephone call to determine which calls are not
completed because they are not answered or busy. As a result processing
complexity and storage requirements are significantly reduced.