Voice Fraud & Compliance Wiki

    Call Authentication

    STI-ASAuthentication Service

    The originating-side service that decides an attestation level, builds the PASSporT, signs it, and inserts the Identity header into the outbound SIP INVITE.

    The authentication service typically sits alongside the session border controller or softswitch. When a call is offered, the SBC hands the call details to the STI-AS, which returns a signed Identity header for the outbound leg.

    The attestation decision is the hard part and is entirely the originating provider's responsibility: it depends on customer identity verification and on whether the calling number is one the customer is authorized to use.

    Why it matters to carriers

    The STI-AS is only as trustworthy as the customer data feeding it. Automating attestation from verified number inventory and KYC records is what keeps A attestation defensible.

    Handling sti-as on your own switch

    SipShield scores live SIP traffic with patented AI so the controls behind this term run automatically — and leave the audit trail regulators expect.