Regional Bell operating company (RBOC) is a term describing one of the U.S. regional telephone companies (or their successors) that were created as a result of the breakup of American Telephone and Telegraph Company (AT&T, known also as the Bell System or "Ma Bell") by a U.S. Federal Court consent decree on December 31, 1983. The seven original regional Bell operating companies were Ameritech, Bell Atlantic, BellSouth, NYNEX, Pacific Bell, Southwestern Bell, and US WEST. Each of these companies owned at least two Bell operating companies (Bell operating company). The BOCs were given the right to provide local phone service while AT&T was allowed to retain its long-distance service. The RBOCs and their constituent BOCs are part of the class of local exchange carriers (LECs).
In addition to the RBOCs, there are more than 100 other franchised local telephone companies classed as local exchange carriers. Competitive local exchange carriers (CLECs) are additional companies allowed to compete with the LECs. These include AT&T in some localities and power companies. An interexchange carrier (IXC) is a long-distance carrier that carries traffic between LECs.
Under the Telecommunications Act of 1996, RBOCs and LECs are allowed to compete for long-distance telephone traffic under certain circumstances. RBOCs are generally in competition for digital data and Internet traffic with wireless service providers and cable TV companies. RBOCs are gradually making available new telephone carrier technologies such as ISDN and DSL.