In order to send private calls outbound from your Business VoIP or Wholesale trunk, you will need to specify a privacy SIP header, while still sending the actual phone number of the service. The traditional method of setting the Caller ID number to "anonymous" conflicts with ACMA regulations on the Australian phone network.
Important: This is required under ACMA regulations that caller ID be sent, to facilitate emergency services locating the origin of 000 calls. If the appropriate privacy headers are sent with the call, the number will not be displayed to general users of the phone network, but will be available to emergency services.
Asterisk Dialplan Command:
SIPAddHeader(Privacy: id)
Please note that the method for specifying call anonymity can vary between asterisk versions and configurations. The following commands and variables may be useful or required for some setups:
CALLERPRES()