The selective call acceptance allows controlling incoming calls by making a list of telephone numbers which you are ready to accept. But incoming calls from subscribers that are not listed are directed to the answering machine by which the caller is informed that you do not accept calls at the moment.
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.