Source note · SIP trunk capacity and concurrent call planning
By default Direct Routing tries another SBC in the user's voice routing policy when an outbound INVITE gets 408, 503 or 504; other 4xx and 6xx responses end the call unless FailoverResponseCodes is changed.
Checked 2026-09-24
- Vendor
- Microsoft
- Product
- Teams Phone Direct Routing
- Subsystem
- SBC failover
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-09-24
- Checked
- 2026-09-24
Sources
- New-CsOnlinePSTNGateway (MicrosoftTeams) — Microsoft Learn · tier 2 current vendor documentation · Parameters, '-FailoverResponseCodes' (default value 408, 503, 504)
Cite this note
APA
WarmTransfer. (2026, September 24). SIP trunk capacity and concurrent call planning: source note sip-trunk-capacity-planning-ms-failover-codes. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-trunk-capacity-planning-ms-failover-codes
BibTeX
@misc{warmtransfer-claim-sip-trunk-capacity-planning-ms-failover-codes,
title = {SIP trunk capacity and concurrent call planning: source note sip-trunk-capacity-planning-ms-failover-codes},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-trunk-capacity-planning-ms-failover-codes},
note = {Source note sip-trunk-capacity-planning-ms-failover-codes, checked 2026-09-24}
}