STIR/SHAKEN
A call authentication framework that verifies caller ID to reduce spoofed and robocall traffic on telephone networks.
STIR/SHAKEN (Secure Telephone Identity Revisited / Signature-based Handling of Asserted information using toKENs) is an industry-wide framework implemented across US carriers since 2021 to combat caller ID spoofing. When a call originates from a VoIP provider, the originating carrier digitally signs the call with an attestation level: A (full attestation — the caller is verified and authorized for the number), B (partial attestation), or C (gateway attestation — the call came from outside the network).
Receiving carriers and analytics platforms read this signature. Calls with A-level attestation are much less likely to be labeled 'Spam Risk' or 'Scam Likely' on recipients' phones. Calls without proper attestation — or with failed signature verification — are increasingly displayed with warning labels or blocked entirely by carrier-level spam filters.
Zonitel implements STIR/SHAKEN for all outbound calls originating on our platform, signing them with full A-level attestation when the caller ID matches a number registered to the account. This protects your business calls from being mislabeled as spam, improving answer rates for outbound sales and customer service calls.