We are currently experiencing issues affecting Microsoft Teams SIP phones due to an ongoing Microsoft service incident (TM1519335).
Impact:
Some SIP phones (Yealink or Poly) may be unable to make or receive calls.
Users may experience sign-in or registration issues.
Phones may appear to be signed in but may not function correctly.
Some devices may display a "Service Unavailable" message.
Current Status:
Microsoft has deployed a fix and reported partial service restoration. However, some SIP phones may continue to experience issues while recovery is ongoing.
What You Need to Know:
If your SIP phone is working normally, please avoid signing out or restarting it unnecessarily.
Calling through the Microsoft Teams desktop and web applications is not affected by this incident.
Our IT team is monitoring the situation and will provide further updates as they become available.