my $Star = 0;
  my $Intf = 0;
  my $IHQ  = 0;
  my $IQD  = 0;
  my $OHQ  = 0;
  my $OQD  = 0;
  my $RXBS = 0;
  my $RXPS = 0;
  my $TXBS = 0;
  my $TXPS = 0;
  my $TRTL = 0;

  my $Track = "";

  # ...
  } elsif ( $fields == 10 ) {
    ( $Star, $Intf, $IHQ, $IQD, $OHQ, $OQD, $RXBS, $RXPS, $TXBS, $TXPS, $TRTL )
      = split( ' ', $summary ); 

  # ...
      $Track = join "<<-", $rec, $Intf;
      $interface_bytes{$Track} += $RXBS;
      $Track = join "->>", $rec, $Intf;
      $interface_bytes{$Track} += $TXBS;
  # ...
  }