An extension's availability will be reflected by the color in the upper left hand corner of the Live Extension box.
Green - if the extension is available, with no pending calls
Yellow - if the extension has a call ringing inbound, also if the extension is making an outbound call that has not connected.
Red - if the extension is currently on a call
By default, all online extensions will display. You may chose to view extensions that are offline with the check box displayed below-
You may also use the search bar above to filter the extensions in the Live Extension view. You may search by an extension's name or number.