In order to send calls anonymously via a CM SIP trunk, the following headers need to be included in the SIP invite:
privacy: id</BR> This header defines the call to be anonymous. It overrides any information in the ‘FROM’ header, and overrides it with ‘anonymous’, making sure the CLI is not displayed.
P-Asserted Identity</BR> This header is used to send a valid CLI with an anonymous call. Without this, a call is not accepted by either CM, or the carrier it is routed to.
P-Asserted-Identity: "317612345678" <sip:[email protected]>
Calls with a P-Asserted Identity in non-International number format will be surcharged with €0.25/minute