Is often met in business practice, during calls to organizations at the moment, when the call is transferred to another number or is set on hold, one hears a music in the telephone dynamics.
Outgoing call control system, works by principle, call everybody
excluding those who are blacklisted or call nobody apart those who are in the
“White list”. The system additionally allows to analyze the duration of the
conversation, marks the time and date of the call and the one who has called.