Source : Free On-Line Dictionary of Computing

Dataphone Digital Service
     
         (DDS) The first private-line digital
        service offered by {AT&T}, with data rates typically at 2.4,
        4.8, 9.6 and 56 kilobits per second.  DDS is now part of
        AT&T's {Accunet} family of services.  Most LEC (local exchange
        carriers) and IXC (IntereXchange Carriers) offer similar
        services.
     
        (1995-02-28)