$telnet->dump_log($filename);

##</code><code>##

dump_log - log all I/O in dump format
        $fh = $obj->dump_log;

        $fh = $obj->dump_log($fh);

        $fh = $obj->dump_log($filename);

  This method starts or stops dump format logging of all the object's
  input and output. The dump format shows the blocks read and written
  in a hexadecimal and printable character format. This method is
  useful when debugging, ...