Source note · Teams Phone Direct Routing and SBC certification
Every OPTIONS and INVITE sent to the Microsoft SIP proxy must carry the paired SBC FQDN, matching the certificate CN or SAN, in the Contact header. A Contact header with an IP address is refused with 403 Forbidden.
Checked 2026-09-23
- Vendor
- Microsoft
- Product
- Teams Phone Direct Routing
- Subsystem
- sip-signaling
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-09-23
- Checked
- 2026-09-23
Sources
- Teams Phone System Direct Routing: SIP protocol — Microsoft · tier 2 current vendor documentation · section 'Detailed requirements for Contact header and Request-URI' > 'Contact header'
Cite this note
APA
WarmTransfer. (2026, September 23). Teams Phone Direct Routing and SBC certification: source note teams-direct-routing-contact-header-fqdn. WarmTransfer. https://warmtransfer.net/knowledge/claims/teams-direct-routing-contact-header-fqdn
BibTeX
@misc{warmtransfer-claim-teams-direct-routing-contact-header-fqdn,
title = {Teams Phone Direct Routing and SBC certification: source note teams-direct-routing-contact-header-fqdn},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/teams-direct-routing-contact-header-fqdn},
note = {Source note teams-direct-routing-contact-header-fqdn, checked 2026-09-23}
}