SIP 408 and Microsoft response codes - Microsoft Teams

Publisher

Microsoft

URL

https://learn.microsoft.com/en-us/troubleshoot/microsoftteams/phone-system/direct-routing/microsoft-sip-response-codes-408

Published

2023-10-30

Updated

unknown

Accessed

2026-09-25

HTTP status

200

License

Microsoft Learn content under Microsoft Terms of Use; no-redistribution; short excerpts and locators only

Source notes citing this source

• 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. in context
• 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. in context

Cite this source record

APA

WarmTransfer. (2023, October 30). SIP 408 and Microsoft response codes - Microsoft Teams. WarmTransfer. https://warmtransfer.net/knowledge/sources/ms-ts-dr-sip-codes-408

BibTeX

@misc{warmtransfer-ms-ts-dr-sip-codes-408,
  title  = {SIP 408 and Microsoft response codes - Microsoft Teams},
  author = {{WarmTransfer}},
  year   = {2023},
  url    = {https://warmtransfer.net/knowledge/sources/ms-ts-dr-sip-codes-408},
  note   = {Microsoft, accessed 2026-09-25}
}