Teams Direct Routing response-code failover happens only if the SBC has not sent a non-100 provisional response, to avoid double ringing.
Checked 2026-10-02
failover will only happen in the absence of non-100 provisional responses from the SBC
- Vendor
- Microsoft
- Product
- Teams Direct Routing
- Subsystem
- outbound routing
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-10-02
- Checked
- 2026-10-02
Sources
- Trunk failover on outbound calls - Microsoft Teams — Microsoft · tier 2 current vendor documentation · Section 'Failover of specific SIP codes received from the Session Border Controller (SBC)', first paragraph
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting SIP 408 Request Timeout and calls that get no response: source note sip-408-timeout-troubleshooting-ms-no-failover-after-18x. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-408-timeout-troubleshooting-ms-no-failover-after-18x
BibTeX
@misc{warmtransfer-claim-sip-408-timeout-troubleshooting-ms-no-failover-after-18x,
title = {Troubleshooting SIP 408 Request Timeout and calls that get no response: source note sip-408-timeout-troubleshooting-ms-no-failover-after-18x},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-408-timeout-troubleshooting-ms-no-failover-after-18x},
note = {Source note sip-408-timeout-troubleshooting-ms-no-failover-after-18x, checked 2026-10-02}
}