An SBC that has not sent OPTIONS on the expected interval is demoted: it is not tried first, but it is tried again before a call failure is generated if the other SBCs in the route cannot deliver the call.

Checked 2026-09-25

Vendor
Microsoft
Product
Teams Phone Direct Routing
Subsystem
SBC health monitoring
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 trunk redundancy and failover design: source note sip-trunk-redundancy-design-ms-demotion. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-trunk-redundancy-design-ms-demotion

BibTeX

@misc{warmtransfer-claim-sip-trunk-redundancy-design-ms-demotion,
  title  = {SIP trunk redundancy and failover design: source note sip-trunk-redundancy-design-ms-demotion},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-trunk-redundancy-design-ms-demotion},
  note   = {Source note sip-trunk-redundancy-design-ms-demotion, checked 2026-09-25}
}

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