Toll switching trunk
In telecommunication, a toll switching trunk or toll connecting trunk is a trunk connecting an end office to a toll center as the first stage of concentration for intertoll or long-distance traffic. Operator assistance or participation may be an optional function. In U.S. common carrier telephony service, a toll center designated "Class 4C" is an office where assistance in completing incoming calls is provided in addition to other traffic; a toll center designated "Class 4P" is an office where operators handle only outbound calls, or where switching is performed without operator assistance. Toll switching trunk In