Microsoft response code 1106 with SIP 408 means the callee answered but the SBC never acknowledged Microsoft's 200 OK. Microsoft says to work with the SBC vendor to check the SIP stack and the TCP/TLS connections to the Microsoft connection points.

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

Cite this note

APA

WarmTransfer. (2026, September 25). Troubleshooting Teams Direct Routing: source note teams-direct-routing-troubleshooting-408-no-ack. WarmTransfer. https://warmtransfer.net/knowledge/claims/teams-direct-routing-troubleshooting-408-no-ack

BibTeX

@misc{warmtransfer-claim-teams-direct-routing-troubleshooting-408-no-ack,
  title  = {Troubleshooting Teams Direct Routing: source note teams-direct-routing-troubleshooting-408-no-ack},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/teams-direct-routing-troubleshooting-408-no-ack},
  note   = {Source note teams-direct-routing-troubleshooting-408-no-ack, checked 2026-09-25}
}

Read in context