Microsoft 365 Alert – Service Degradation – Microsoft Teams – Users may have been unable to make or receive Public Switched Telephone Network (PSTN) calls in Microsoft Teams – RESOLVED

11/09/2023 12:09:00 PM (GMT)

Microsoft Reference : TM673780

Issue Status : RESOLVED

Issue Description : Users may have been unable to make or receive PSTN calls in Microsoft Teams.

Current Update : 11/09/2023 12:09:00 PM – Microsoft identified that a section of networking infrastructure, that facilitates PSTN calls in Microsoft Teams, had fallen below their manageable service performance thresholds and resulted in impact. They have rerouted affected traffic to the alternate healthy infrastructure and impact has been remediated after a period of monitoring.

Scope of impact : Impact was specific to some users who were served through the Europe, Middle East, and Africa region.

Root cause : A section of networking infrastructure, that facilitates PSTN calls in Microsoft Teams, had fallen below their manageable service performance thresholds and resulted in impact.

Next steps : Microsoft are analyzing performance data and trends on the affected infrastructure to help prevent this problem from happening again.