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.
IDC projected over 9 billion minutes of voice traffic to travel over worldwide packet networks in 2000, exceeding 135 billion minutes in 2004. Service revenue is projected at 1.6 billion in 2000 and 18.7 billion in 2004.