An ILEC, or Incumbent Local Exchange Carrier is essentially the original owner of telecommunication lines, switching equipment, and other related infrastructure associated with the LEC.  This would describe, for example, AT&T, Bell South, or any of the “baby bells” that held monopolies in various geographical areas prior to the introduction of the 1996 Telecom Act. Since 1996, ILECS have been legally obligated to lease out to smaller regional, national, or long distance competitive carriers.  Those parts of the system are designated as a CLEC (Competitive Local Exchange Carriers).