Call Authentication
Evidence that a customer is genuinely authorized to use the telephone numbers they present as caller ID.
Proof of possession can take several forms: numbers assigned directly by you, a Letter of Authorization from the number's rightful subscriber, a successful callback or SMS verification to the number, or a carrier port record.
Without proof of possession, a call cannot honestly be signed with A attestation, regardless of how well you know the customer as a business.
Proof of possession is the single most-abused gap in STIR/SHAKEN. Accepting a customer's word that they own a number is how legitimate carriers end up A-signing spoofed traffic.
The three confidence levels an originating carrier assigns when signing a call, describing how well it knows the customer and their right to use the calling number.
The process of verifying who a voice customer really is, what traffic they intend to send, and whether they are authorized to use the numbers they present.
Presenting a calling number the caller is not authorized to use, in order to disguise the call's true origin or impersonate a trusted party.
The originating-side service that decides an attestation level, builds the PASSporT, signs it, and inserts the Identity header into the outbound SIP INVITE.
SipShield scores live SIP traffic with patented AI so the controls behind this term run automatically — and leave the audit trail regulators expect.