The Direct Routing FailoverResponseCodes setting (default 408, 503, 504) applies to responses to an SBC-terminated initial INVITE. It does not concern OPTIONS.

Checked 2026-09-24

Vendor
Microsoft
Product
Teams Phone Direct Routing
Subsystem
New-CsOnlinePSTNGateway
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-failover-codes-invite-only. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-options-keepalive-dr-failover-codes-invite-only

BibTeX

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

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