Source : Free On-Line Dictionary of Computing

High-level Data Link Control
     
         (HDLC) A general-purpose {data link} control
        {protocol} defined by {ISO} for use on both point-to-point and
        {multipoint} (multidrop) data links.  It supports
        {full-duplex}, {transparent-mode} operation.  It is used
        extensively in both multipoint and computer networks.
     
        Some manufacturers and other standards bodies still use their
        own acronyms, e.g. {IBM}'s SDLC ({Synchronous Data Link
        Control}), the forerunner of HDLC and {ANSI}'s ADCCP
        ({Advanced Data Communications Control Procedure}).
     
        [Fred Halsall, "Data Communications, Computer Networks and
        Open Systems" 4th edition, 1996, p.237, Addison-Wesley
        Publishing Co. Reading, Mass., USA].
     
        (1997-11-09)