Teams Direct Routing maps the SBC to a tenant by the FQDN in its Contact or Record-Route header, so an IP address in Contact or an FQDN that differs from the Teams configuration causes SIP OPTIONS to fail.
Checked 2026-10-02
- Vendor
- Microsoft
- Product
- Teams Direct Routing
- Subsystem
- SBC identity
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-10-02
- Checked
- 2026-10-02
Sources
- SBC connectivity issues — Microsoft · tier 2 current vendor documentation · Issues related to SIP OPTIONS: 'The SBC doesn't receive a SIP 200 OK response from the SIP proxy'
Cite this note
APA
WarmTransfer. (2026, October 2). SIP trunk authentication: registration and static IP and mutual TLS: source note sip-trunk-authentication-models-teams-dr-contact-fqdn. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-trunk-authentication-models-teams-dr-contact-fqdn
BibTeX
@misc{warmtransfer-claim-sip-trunk-authentication-models-teams-dr-contact-fqdn,
title = {SIP trunk authentication: registration and static IP and mutual TLS: source note sip-trunk-authentication-models-teams-dr-contact-fqdn},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-trunk-authentication-models-teams-dr-contact-fqdn},
note = {Source note sip-trunk-authentication-models-teams-dr-contact-fqdn, checked 2026-10-02}
}