SIP 488 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-488

Published

2024-11-22

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 531052 with SIP 488 ('Cannot negotiate a new modality with blackhole media') means the SBC sent SDP with connection address 0.0.0.0, which the Microsoft SIP stack doesn't support. in context
• Microsoft response code 531027 with SIP 488 ('There are no ICE candidates in the SDP') means media bypass failed because the SBC's SDP had no ICE candidates. Microsoft's fix is to enable ICE Lite on the SBC. in context
• Microsoft response code 531000 with SIP 488 has two forms. CannotSupportAnyMedia means the SBC offered no acceptable media format, so check its codec configuration. SrtpEncryptionRequired means the SBC didn't offer SRTP, so enable SRTP on the SBC. in context

Cite this source record

APA

WarmTransfer. (2024, November 22). SIP 488 and Microsoft response codes - Microsoft Teams. WarmTransfer. https://warmtransfer.net/knowledge/sources/ms-ts-dr-sip-codes-488

BibTeX

@misc{warmtransfer-ms-ts-dr-sip-codes-488,
  title  = {SIP 488 and Microsoft response codes - Microsoft Teams},
  author = {{WarmTransfer}},
  year   = {2024},
  url    = {https://warmtransfer.net/knowledge/sources/ms-ts-dr-sip-codes-488},
  note   = {Microsoft, accessed 2026-09-25}
}