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SIP response code 420

  • Article
  • Applies to:
    Microsoft Teams

This article provides troubleshooting information for the combination of the SIP 420 error and Microsoft response code 560420.

560420 420 Bad Extension

  • Microsoft response code: 560420
  • SIP response code: 420
  • Suggested actions:
    • Check the SBC configuration to make sure that it's configured to support the required headers, such as the Replaces header. If necessary, work with your SBC vendor to verify that the SBC is configured correctly to support the required SIP protocol extension.