Within the core, or backbone, of a Wide Area Network (WAN), transport circuits, or long haul circuits, carry data over long distances. Long haul traditionally is defined as a distance equal to or greater than 50 miles (80 kilometers). A short haul circuit, therefore, is less than 50 miles. Access circuits, aka local loops, are short haul circuits.A local area network (LAN) definitely involves short haul circuits. See also access circuit, LAN, local loop, and WAN.