Several users are reporting problems joining meetings and making Teams calls. Calls either fail to connect or connect without audio, but the service health dashboard initially showed nothing. Is anyone else seeing this, and has Microsoft acknowledged an outage?
3 Answers
If this turns out to be local or recurring, check the network configuration. We previously found Teams traffic failing over UDP 443 because it wasn’t allowed through our firewall. Teams endpoint ranges and domains had also changed, so updating the allowlists and opening the required UDP traffic resolved our call issues.
We had the same behavior: a user tried calling twice and received “Sorry, we couldn’t connect you.” Calling from the other side produced the same result, while switching to a mobile phone worked. The issue may be regional or service-side rather than a local client problem.
Yes, there appears to be an active Microsoft service incident, listed as TM1475580. We’ve seen calls fail with connection errors and meetings where participants can’t hear one another. The impact seems particularly noticeable for users in France and Spain.

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