One cause of an intermittently inactive SBC is sending OPTIONS to fixed IP addresses instead of the SIP proxy FQDNs. During maintenance or outages those IPs can move to another datacenter. Microsoft's fix is to send OPTIONS only to FQDNs and to configure all three: sip, sip2 and sip3.pstnhub.microsoft.com.

Checked 2026-09-25

Vendor
Microsoft
Product
Microsoft Teams Phone Direct Routing
Subsystem
sbc-status
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-intermit-ip-pin. WarmTransfer. https://warmtransfer.net/knowledge/claims/teams-direct-routing-troubleshooting-intermit-ip-pin

BibTeX

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

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