Source note · SIP TLS handshake failures on trunks
If TLS is established but the SBC gets no 200 OK to its OPTIONS, Microsoft points to SIP-layer causes: the Record-Route or Contact FQDN differs from the Teams configuration, the Contact carries an IP address, or the domain is not fully validated.
Checked 2026-09-25
- Vendor
- Microsoft
- Product
- Teams Phone Direct Routing
- Subsystem
- SIP OPTIONS
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-09-25
- Checked
- 2026-09-25
Sources
- SBC connectivity issues — Microsoft · tier 2 current vendor documentation · SIP options issues > SBC doesn't receive a "200 OK" response from SIP proxy
Cite this note
APA
WarmTransfer. (2026, September 25). SIP TLS handshake failures on trunks: source note sip-tls-handshake-failures-dr-no-200ok-fqdn. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-tls-handshake-failures-dr-no-200ok-fqdn
BibTeX
@misc{warmtransfer-claim-sip-tls-handshake-failures-dr-no-200ok-fqdn,
title = {SIP TLS handshake failures on trunks: source note sip-tls-handshake-failures-dr-no-200ok-fqdn},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-tls-handshake-failures-dr-no-200ok-fqdn},
note = {Source note sip-tls-handshake-failures-dr-no-200ok-fqdn, checked 2026-09-25}
}