"Do you want to configure dynamic lines?"

    If you want to establish a dynamic asynchronous connection,
    answer YES. A dynamic asynchronous connection provides a
    temporary DECnet link. A dynamic asynchronous line is normally
    switched on for network use only for the duration of a dialup
    connection between two nodes. When the telephone is hung up,
    the line reverts to being a terminal line. The advantage of this
    type of connection is that you can use a single line to establish
    dynamic connections to different remote nodes at different times.