DEFINE TYPE DynamicPortType 
  ( value     : PortNumberType,
    min       : PortNumberType  STATIC :=   49152,
    max       : PortNumberType  STATIC :=   65535,
    default   : PortNumberType  STATIC :=   30303,
    units     : PortNumberType  STATIC := "PortNumber"
  ) AS
  PortNumberType
  ALLOWING NONULL
  WITH CONSTRAINTS
    ( VALUE     = default,
      MIN       = min,
      MAX       = max,
      DEFAULT   = default,
      UNITS     = units
    );