If the TLS connection closes immediately and no OPTIONS arrive from the SBC, or no 200 OK comes back from the SBC, Microsoft suggests checking the TLS version. The SBC should be configured for TLS 1.2 or higher.

Checked 2026-09-25

The TLS version configured on the SBC should be 1.2 or higher.
Vendor
Microsoft
Product
Microsoft Teams Phone Direct Routing
Subsystem
tls
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). Troubleshooting Teams Direct Routing: source note teams-direct-routing-troubleshooting-tls-12. WarmTransfer. https://warmtransfer.net/knowledge/claims/teams-direct-routing-troubleshooting-tls-12

BibTeX

@misc{warmtransfer-claim-teams-direct-routing-troubleshooting-tls-12,
  title  = {Troubleshooting Teams Direct Routing: source note teams-direct-routing-troubleshooting-tls-12},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/teams-direct-routing-troubleshooting-tls-12},
  note   = {Source note teams-direct-routing-troubleshooting-tls-12, checked 2026-09-25}
}

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