RFC 8588 does not define the meaning of the A, B and C attestation levels itself; it points to ATIS-1000074 for those definitions.
Checked 2026-10-02
- Vendor
- not restricted
- Product
- not restricted
- Subsystem
- SHAKEN PASSporT
- Deployment
- carrier
- Region
- not restricted
- Release range
- RFC 8588
- Checked
- 2026-10-02
Sources
- RFC 8588: Personal Assertion Token (PaSSporT) Extension for Signature-based Handling of Asserted information using toKENs (SHAKEN) — IETF / RFC Editor · tier 1 standards and regulators · RFC 8588 section 4
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting STIR/SHAKEN attestation levels on outbound calls: source note stir-shaken-attestation-troubleshooting-rfc8588-atis-defs. WarmTransfer. https://warmtransfer.net/knowledge/claims/stir-shaken-attestation-troubleshooting-rfc8588-atis-defs
BibTeX
@misc{warmtransfer-claim-stir-shaken-attestation-troubleshooting-rfc8588-atis-defs,
title = {Troubleshooting STIR/SHAKEN attestation levels on outbound calls: source note stir-shaken-attestation-troubleshooting-rfc8588-atis-defs},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/stir-shaken-attestation-troubleshooting-rfc8588-atis-defs},
note = {Source note stir-shaken-attestation-troubleshooting-rfc8588-atis-defs, checked 2026-10-02}
}