When Direct Routing receives OPTIONS from an SBC, it starts sending its own OPTIONS to the SBC FQDN given in the Contact header of those incoming OPTIONS.

Checked 2026-09-24

When Direct Routing sees incoming OPTIONS, it starts sending outgoing SIP Options messages to the SBC FQDN configured in the Contact header field in the incoming OPTIONS message.
Vendor
Microsoft
Product
Teams Phone Direct Routing
Subsystem
SBC pairing
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-proxy-options-contact. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-options-keepalive-dr-proxy-options-contact

BibTeX

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

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