Sec. 101.511  Purpose and permissible service.

    (a) The DEMS is intended to provide for the exchange of digital 
information among and between subscribers using one or more DEMS 
Systems.
    (b) Unless otherwise directed or conditioned in the applicable 
instrument of authorization, DEMS may be used to exchange any type of 
digital information consistent with the Commission's Rules and the 
applicable tariff of the carrier.
    (c) The carrier's tariff must fully describe the parameters of the 
service to be provided, including the degree of communications security 
a subscriber can expect in ordinary service.