Microsoft 365 Alert – Service Degradation – Microsoft Teams – Some users may be unable to receive Public Switched Telephone Network (PSTN) calls in Microsoft Teams – RESOLVED

Announcements Arpan Das

22/07/2024 09:06:00 AM

NHSmail Reference: INC44473368

Microsoft Reference: TM822958

Issue Status: RESOLVED

Issue Description: Some users may be unable to receive Public Switched Telephone Network (PSTN) calls in Microsoft Teams.

More info: This issue may affect any Microsoft Teams user with a PSTN phone number that was provisioned between Thursday, July 18, 2024, at 10:00 PM UTC, and Friday, July 19, 2024, at 5:00 AM UTC. Other users are unaffected.

Final Update: 23/07/2024 09:15:00 AM – After repopulating the PSTN phone number data that became affected by the recent Microsoft Teams infrastructure performance degradation, Microsoft have confirmed with affected users that impact has been remediated.

Scope of impact: This issue may have affected any user with a PSTN phone number that was provisioned between Thursday, July 18, 2024, at 10:00 PM UTC, and Friday, July 19, 2024, at 5:00 AM UTC.

Root cause: A recent performance degradation in the Microsoft Teams infrastructure responsible for maintaining PSTN phone numbers caused some phone number data to be depopulated, resulting in impact.

Next steps: Microsoft are further analyzing the affected Microsoft Teams infrastructure and the isolated performance degradation to help them identify and prevent similar issues in the future.