The TLS handshake_failure alert (40) means the sender could not negotiate an acceptable set of security parameters from the options offered.

Checked 2026-09-25

Vendor
IETF
Product
TLS
Subsystem
TLS alerts
Deployment
any
Region
not restricted
Release range
TLS 1.3 (RFC 8446); same code in TLS 1.2
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). SIP TLS handshake failures on trunks: source note sip-tls-handshake-failures-rfc8446-handshake-failure. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-tls-handshake-failures-rfc8446-handshake-failure

BibTeX

@misc{warmtransfer-claim-sip-tls-handshake-failures-rfc8446-handshake-failure,
  title  = {SIP TLS handshake failures on trunks: source note sip-tls-handshake-failures-rfc8446-handshake-failure},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-tls-handshake-failures-rfc8446-handshake-failure},
  note   = {Source note sip-tls-handshake-failures-rfc8446-handshake-failure, checked 2026-09-25}
}

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