Call Authentication
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.
A attestation (Full) means the provider authenticated the customer and confirmed they are authorized to use the calling number. B attestation (Partial) means the provider authenticated the customer but cannot confirm the number belongs to them. C attestation (Gateway) means the provider is simply passing along a call it received from elsewhere, typically an international gateway, and knows nothing about the origin.
Attestation is asserted by the originating provider, not verified by anyone downstream. That is why analytics engines treat C-attested traffic with suspicion and why heavy C volumes attract regulatory attention.
Persistently signing B or C when you could sign A depresses your call completion and answer rates. Signing A for traffic you have not properly vetted exposes you to enforcement when that traffic turns out to be illegal.
The FCC-mandated framework that cryptographically signs calling numbers so terminating carriers can verify the caller ID was not spoofed.
Evidence that a customer is genuinely authorized to use the telephone numbers they present as caller ID.
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.
The signed JSON Web Token inside the Identity header that asserts the calling number, called number, attestation level, and origination identifier.
SipShield scores live SIP traffic with patented AI so the controls behind this term run automatically — and leave the audit trail regulators expect.