. AT&T and other local telephone companies had to provide "tail circuits" to the SCCs, whose networks were less extensive and did not include local facilities. Its private line rates were highly distance-sensitive; the SCCs specialized in the long-haul middle section of intercity routes. So AT&T began to lower the cost of long-haul circuits, raising the cost of shorter ones. It introduced the "hi-lo" tariff. This provided for low mileage rates between certain designated major cities, and higher rates everywhere else. Thus a single AT&T private line between two distant but smaller towns could be priced by paying the higher rate to the nearest major city, the lower rate for the long haul, and the higher rate to the distant destination town. This more closely mir- rored the cost structure of using a low-priced SCC. Faced with regulatory chal- lenges, AT&T then replaced hi-lo with a newer mileage-based rate structure called multischedule private line (MPL). This was based on declining-block mileage rates, such that, for example, the first mile was much more expensive than the 1,001 mile. But there were three different rate schedules, depending on whether either, both, or neither end point was in a high-density city. This rate structure remained in place until divestiture. Divestiture, of course, put AT&T and its former competitors on an equal footing; inter-LATA (local access and transport area) circuits thenceforth consisted of discrete special access tail circuits from the local exchange carriers, connecting to long-haul carriers at a point of presence (PoP) at either end. The Great Telecom Meltdown Execunet Gives Birth to Competitive Long Distance The original SCC authorizations did not specifically include switched services; both message toll service (MTS, or conventional long distance) and wide area telephone service (WATS, or bulk long distance) were expected to remain monopolies. But the SCCs were allowed to provide foreign exchange (FX) serv- ice. This consisted of a leased line into a distant telephone centr