SIP response code 488

• Applies to:

  Microsoft Teams

This article provides troubleshooting information for various combinations of the SIP 488 error and Microsoft response codes.

531000 488 InternalDiagCode: CannotSupportAnyMedia, InternalErrorPhrase: Invalid SDP offer: no media acceptable

• Microsoft response code: 531000
• SIP response code: 488
• Suggested actions:
  • Check the SBC configuration to determine why it offers unsupported media formats. For more information about supported codecs, see Leg between SBC and Cloud Media Processor or Microsoft Teams client.

531000 488 InternalDiagCode: SrtpEncryptionRequired, InternalErrorPhrase: Remote participant did not offer required SRTP support

• Microsoft response code: 531000
• SIP response code: 488
• Suggested actions:
  • Enable Secure Real-time Transport Protocol (SRTP) on the SBC.

531027 488 There are no ICE candidates in the SDP. Non-ice endpoints cannot use bypass

• Microsoft response code: 531027
• SIP response code: 488
• Suggested actions:
  • Media bypass doesn't work if the SBC doesn't provide any ICE candidates in its SDP offer. Make sure that you enable ICE Lite on the SBC. For more information about media bypass, see About Media Bypass with Direct Routing and Direct Routing - media protocols.

531052 488 Cannot negotiate a new modality with blackhole media

• Microsoft response code: 531052
• SIP response code: 488
• Suggested actions:
  • Check the SBC configuration to determine why it sends an SIP message with SDP that has a connection address of 0.0.0.0. Microsoft SIP stack doesn't support this scenario. For more information, see Deviations from the RFCs.