Because the Teams Direct Routing failover timer defaults to 10 seconds, an SBC that answers slowly can see Microsoft abandon or fail over the INVITE well before the 32-second RFC Timer B would expire.
inferred · Checked 2026-10-02
- Vendor
- Microsoft
- Product
- Teams Direct Routing
- Subsystem
- outbound routing
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-10-02
- Status
- inferred
- Checked
- 2026-10-02
Sources
- SIP 408 and Microsoft response codes - Microsoft Teams — Microsoft · tier 2 current vendor documentation · Section '500001 408 Gateway (SBC) failover timer expired' compared with RFC 3261 17.1.1.2
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-inf-teams-failover-before-b. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-408-timeout-troubleshooting-inf-teams-failover-before-b
BibTeX
@misc{warmtransfer-claim-sip-408-timeout-troubleshooting-inf-teams-failover-before-b,
title = {Troubleshooting SIP 408 Request Timeout and calls that get no response: source note sip-408-timeout-troubleshooting-inf-teams-failover-before-b},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-408-timeout-troubleshooting-inf-teams-failover-before-b},
note = {Source note sip-408-timeout-troubleshooting-inf-teams-failover-before-b, checked 2026-10-02}
}