The current release of IP Office does not have the ability to include the necessary Diversion header for Verizon’s Unscreened ANI feature. IPOFFICE-48189 was created to add this ability. The Diversion header would include a Verizon assigned STN number to be presented with the SIP invite to allow the call to go through. In the past, Verizon allowed the STN number to be presented in the PAI header as well, but they have since changed their approach to only accepting the Diversion header.
The current release of IP Office can be programmed to send the STN in the PAI header, but Verizon would have to agree to accept it as a variant for this one customer. Or, an SBC would be needed to change the PAI header into a Diversion header for Unscreened ANI calls.
