Creates an instance of a ddcmp link entity which defines
    the attributes of a link to a communications port that uses
    DDCMP.

    create  [node node-id] ddcmp -
        link link-name [protocol protocol-type]

    The optional Protocol argument specifies the protocol mode used
    by the local station.

    point      The local station is one end of a point-to-point link.
               This is the default and only supported value.

    tributary  The local station acts as a tributary of a multipoint
               link.

    Example:

    create ddcmp link ddcmp-0

    Select logical_station for information on creating ddcmp link
    logical station subentities.