Source note · SIP OPTIONS pings and trunk keepalives

Causes Microsoft lists for an SBC getting no 200 OK to its OPTIONS include: a Contact header carrying an IP address instead of the FQDN, an FQDN in Record-Route or Contact that differs from the one configured in Teams, and a domain that is not fully validated or not activated.

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

SBC connectivity issues — Microsoft · tier 2 current vendor documentation · section 'SIP options issues' > 'SBC doesn't receive a "200 OK" response from SIP proxy'

Cite this note

APA

WarmTransfer. (2026, September 24). SIP OPTIONS pings and trunk keepalives: source note sip-options-keepalive-dr-contact-ip-no-200. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-options-keepalive-dr-contact-ip-no-200

BibTeX

@misc{warmtransfer-claim-sip-options-keepalive-dr-contact-ip-no-200,
  title  = {SIP OPTIONS pings and trunk keepalives: source note sip-options-keepalive-dr-contact-ip-no-200},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-options-keepalive-dr-contact-ip-no-200},
  note   = {Source note sip-options-keepalive-dr-contact-ip-no-200, checked 2026-09-24}
}

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