A call is active and the local tab is connected to the call, however there is currently no other participant in the call.
A call is active and the local person has joined it on an other device.
A call is active but the local person has declined it.
A some one is trying to call, the phone is ringing
No inbound, outgoing or active call.
You are trying to call someone
A call is active and the local tab is connected to the call and there is at least one other participant to which the connection is established.