A Competitive Local Exchange Carrier (CLEC), in the United States, is a telecommunications provider company (sometimes called a "carrier") that competes with other, already established carriers (generally the incumbent local exchange carrier (ILEC)).Local exchange carriers (LECs) are divided into incumbent (ILECs) and competitive (CLECs). The ILECs are usually the original, monopoly LEC in a given area, and receive different regulatory treatment from the newer CLECs. A Data Local Exchange Carrier (DLEC) is a CLEC that specializes in DSL services by leasing lines from the CLEC and reselling them to Internet Service Providers (ISPs).
See more at Wikipedia.org...