For ACS direct routing SIP signaling the SBC must be able to negotiate one of four cipher suites: TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 or TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256.

Checked 2026-09-25

Vendor
Microsoft
Product
Azure Communication Services direct routing
Subsystem
cipher negotiation
Deployment
multi-tenant
Region
not restricted
Release range
current as of 2026-09-25
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-acs-cipher-list. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-tls-handshake-failures-acs-cipher-list

BibTeX

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

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