Source note · SIP trunk redundancy and failover design
For Microsoft 365, Office 365 and GCC, Direct Routing SBCs are configured with three SIP proxy FQDNs in priority order: sip.pstnhub.microsoft.com (primary), sip2.pstnhub.microsoft.com (secondary) and sip3.pstnhub.microsoft.com (tertiary).
Checked 2026-09-25
- Vendor
- Microsoft
- Product
- Teams Phone Direct Routing
- Subsystem
- SIP signaling
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-09-25
- Checked
- 2026-09-25
Sources
- Plan Direct Routing — Microsoft (Microsoft Learn) · tier 2 current vendor documentation · SIP signaling: FQDNs table
Cite this note
APA
WarmTransfer. (2026, September 25). SIP trunk redundancy and failover design: source note sip-trunk-redundancy-design-ms-proxy-fqdns. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-trunk-redundancy-design-ms-proxy-fqdns
BibTeX
@misc{warmtransfer-claim-sip-trunk-redundancy-design-ms-proxy-fqdns,
title = {SIP trunk redundancy and failover design: source note sip-trunk-redundancy-design-ms-proxy-fqdns},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-trunk-redundancy-design-ms-proxy-fqdns},
note = {Source note sip-trunk-redundancy-design-ms-proxy-fqdns, checked 2026-09-25}
}