Source note · Troubleshooting Teams Direct Routing
Microsoft response code 500001 with SIP 408 ('Gateway (SBC) failover timer expired') means the SBC didn't answer the INVITE within FailoverTimeSeconds, which defaults to 10 seconds. In regions with long PSTN setup times, Microsoft suggests raising it to 20 seconds.
Checked 2026-09-25
- Vendor
- Microsoft
- Product
- Microsoft Teams Phone Direct Routing
- Subsystem
- sip-response-codes
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-09-25
- Checked
- 2026-09-25
Sources
- SIP 408 and Microsoft response codes - Microsoft Teams — Microsoft · tier 2 current vendor documentation · 500001 408 Gateway (SBC) failover timer expired
Cite this note
APA
WarmTransfer. (2026, September 25). Troubleshooting Teams Direct Routing: source note teams-direct-routing-troubleshooting-408-failover. WarmTransfer. https://warmtransfer.net/knowledge/claims/teams-direct-routing-troubleshooting-408-failover
BibTeX
@misc{warmtransfer-claim-teams-direct-routing-troubleshooting-408-failover,
title = {Troubleshooting Teams Direct Routing: source note teams-direct-routing-troubleshooting-408-failover},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/teams-direct-routing-troubleshooting-408-failover},
note = {Source note teams-direct-routing-troubleshooting-408-failover, checked 2026-09-25}
}