PSTN: Operational and Regulatory Issues

Public Telephone and Telegraph (PTT) organizations are the highest-level monopoly
(or ex-monopoly) in each country, and generally are expected to comply with ITUT
standards for interoperability. Each PTT is regulated by its country of origin. In
the United States,AT&T was broken up in 1982 into a long distance unit (AT&T as
the Inter-exchange carrier (IXC) was authorized only to carry long distance traffic),
and reorganized groups of regional Bell Operating Companies were given a limited
Local Exchange Carrier (LEC) role that until recently prevented them from selling
interstate (or interLATA) long distance services. Competitive LECs (CLECs), in spite
of regulatory advantages, hold less than 10% of local lines.