资料来源 : Free On-Line Dictionary of Computing

dedicated line
     
         A telephone line leased expressly for the
        purpose of connecting two users more-or-less permenantly..
        Such lines may be "voice grade" which provides the {bandwidth}
        and {signal to noise ratio} of ordinary {public switched
        telephone network} circuits, or specified in ways which allow
        transport of suitably encoded digital signals at faster rates.
     
        In some cases, lines may be physical wires between the
        communicating parties.  Over longer distances, it is common
        for the connection to be virtual, which means that although
        the two users can communicate only with each other, their
        signals and others are multiplexed, amplified, switched,
        scrambled, demultiplexed and so on in complex ways between the
        end points.
     
        This contrasts with a {dial-up} connection which is only
        opened when one end requires it.
     
        (1996-08-10)