If you are in a conversation with another person, you can call this person.
If the person you are calling is already on a call, a tone will notify him or her that someone else is trying to call.
If the user that you are trying to call has made himself or herself unavailable, the call icon on this screen is red.
You can tap this icon to make an urgent call to this user if the group to which you belong has been granted permission to make urgent calls.
If you answer a cellular call on your device, your Vocera call is disconnected. This includes any call that is on hold.