15-10-2021 05:32:00 PM (BST)
Microsoft Reference : TM291829
Issue Status: RESOLVED
Issue Description: Some users may experience various issues with PSTN calls or meetings in Microsoft Teams.
Users may have experienced the following:
– Unable to create outbound 1 to 1 VOIP or Public Switched Telephone Network (PSTN) calls.
– Unable to add participants to existing meetings.
– Unable to receive any PSTN calls.
Scope of impact: Any user hosted on infrastructure which received this update may have experienced impact.
Final Update – 15/10/2021 05:32:00 PM: Microsoft investigation is complete and have determined that impact occurred due to a recent Encryption Control System (ECS) update which resulted in degradation within Microsoft Teams as outlined above in the ‘More info’ section. To remediate the issue, Microsoft have reverted this update and have confirmed via monitoring service telemetry that impact has been resolved.