By default, When you are in a Teams video or voice call and somebody else calls you everything goes wrong.

You get muted and cant hear / speak to the person already in a call.

The new caller gets a ring tone and you are deafened by a ringer in your ear or PC speaker.

 

The fix is fairly simple. You can configure Teams to show busy when you are in a call. Then a new caller gets a busy message and you get a missed call notification if you are already in a conversation.

  1. Connect to your Microsoft Teams Admin Center.
  2. Go to Voice and select Calling policies.
  3. Then click on Global.
  4. Toggle on Busy on busy is available when in a call.

 

in Microsoft Office & 365