Source note · SIP TLS handshake failures on trunks
A wildcard SBC certificate that Teams Direct Routing accepts under RFC 2818 rules may still be rejected by a SIP peer that validates strictly under RFC 5922, so a wildcard that works toward Microsoft is no evidence it will work on a carrier or PBX trunk.
inferred · Checked 2026-09-25
- Vendor
- multi-vendor
- Product
- SIP trunks over TLS
- Subsystem
- server identity validation
- Deployment
- any
- Region
- not restricted
- Release range
- current as of 2026-09-25
- Status
- inferred
- Checked
- 2026-09-25
Sources
- RFC 5922: Domain Certificates in the Session Initiation Protocol (SIP) — RFC Editor / IETF · tier 1 standards and regulators · Section 7.2, read against Plan Direct Routing > Public trusted certificate for the SBC
Cite this note
APA
WarmTransfer. (2026, September 25). SIP TLS handshake failures on trunks: source note sip-tls-handshake-failures-wildcard-standard-gap. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-tls-handshake-failures-wildcard-standard-gap
BibTeX
@misc{warmtransfer-claim-sip-tls-handshake-failures-wildcard-standard-gap,
title = {SIP TLS handshake failures on trunks: source note sip-tls-handshake-failures-wildcard-standard-gap},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-tls-handshake-failures-wildcard-standard-gap},
note = {Source note sip-tls-handshake-failures-wildcard-standard-gap, checked 2026-09-25}
}