An SBC that sends OPTIONS to fixed IP addresses rather than to the SIP proxy FQDNs can show as intermittently inactive, because those addresses can move to another datacenter during maintenance or outages. Microsoft says to send OPTIONS to FQDNs only and to configure all three proxy FQDNs.

Checked 2026-09-24

Vendor
Microsoft
Product
Teams Phone Direct Routing
Subsystem
troubleshooting
Deployment
multi-tenant
Region
not restricted
Release range
current as of 2026-09-24
Checked
2026-09-24

Sources

Cite this note

APA

WarmTransfer. (2026, September 24). SIP OPTIONS pings and trunk keepalives: source note sip-options-keepalive-dr-options-to-fqdn. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-options-keepalive-dr-options-to-fqdn

BibTeX

@misc{warmtransfer-claim-sip-options-keepalive-dr-options-to-fqdn,
  title  = {SIP OPTIONS pings and trunk keepalives: source note sip-options-keepalive-dr-options-to-fqdn},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-options-keepalive-dr-options-to-fqdn},
  note   = {Source note sip-options-keepalive-dr-options-to-fqdn, checked 2026-09-24}
}

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