Source note · Troubleshooting SIP 403 Forbidden from a carrier
A 403 that a carrier attributes to STIR/SHAKEN attestation level is carrier local policy rather than standardised behaviour, because the STIR and SHAKEN RFCs examined define 403 only for stale Date or iat values and define no rejection by attestation level.
inferred · Checked 2026-09-30
- Vendor
- IETF
- Product
- STIR SHAKEN
- Subsystem
- verification service
- Deployment
- any
- Region
- not restricted
- Release range
- current as of 2026-09-30
- Status
- inferred
- Checked
- 2026-09-30
Sources
- RFC 8224: Authenticated Identity Management in the Session Initiation Protocol (SIP) — IETF / RFC Editor · tier 1 standards and regulators · sections 6.2.1 and 6.2.2 read together with RFC 8588 sections 4 and 9
Cite this note
APA
WarmTransfer. (2026, September 30). Troubleshooting SIP 403 Forbidden from a carrier: source note sip-403-forbidden-troubleshooting-attest-403-policy. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-403-forbidden-troubleshooting-attest-403-policy
BibTeX
@misc{warmtransfer-claim-sip-403-forbidden-troubleshooting-attest-403-policy,
title = {Troubleshooting SIP 403 Forbidden from a carrier: source note sip-403-forbidden-troubleshooting-attest-403-policy},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-403-forbidden-troubleshooting-attest-403-policy},
note = {Source note sip-403-forbidden-troubleshooting-attest-403-policy, checked 2026-09-30}
}