Microsoft 365 Alert – Service Degradation – Microsoft Teams – Users can’t make or receive Public Switched Telephone Network (PSTN) calls in Microsoft Teams – RESOLVED

17/08/2023 09:25:00 AM (GMT)

NHSmail Reference : INC37698583

Microsoft Reference : TM668086

Issue Status : RESOLVED

Issue Description : Users can’t make or receive Public Switched Telephone Network (PSTN) calls in Microsoft Teams.

More info : This only impacted users who had their phone numbers assigned between Monday, August 14, 2023, at 8:30 PM UTC, and Wednesday, August 16, 2023, at 2:00 AM UTC. Impacted users could have still performed peer-to-peer Voice over IP (P2P VoIP) calls through Microsoft Teams.

Final Update : 18/08/2023 08:22:00 AM – Microsoft verified with some affected users, and further observed through their continued monitoring of service health, that their fix to fully address the underlying problem has remediated the issue.

Scope of impact : Your organization is affected by this event, and any user attempting to make or receive PSTN calls in Microsoft Teams is impacted.

Root cause : A recent service update contained a configuration issue that prevented phone numbers from being properly assigned to users, resulting in impact.

Next steps : Microsoft are reviewing their service update procedures so they can better identify similar issues during the testing and development cycles and avoid comparable impact in the future