Recently I played with the tcng-9d and found that tcsim_filter script
does produce broken output that can't be used with tcsim_plot -t delay.
As far as I see, tcsim_plot use remaining part (after "packet length"
field) of input string to identify enqueued/dequeued packets, but
tcsim_filter does not produce it. So here is the pacth for tcsim_filter
to produce unique packet identifier in the last output field based on
simulated skbuff address (that _is unique_ for any enqueued packet in
the simulated qdisc).

Dimitry.

--- tcsim_filter.orig	Fri Sep 20 04:14:21 2002
+++ tcsim_filter	Sun Apr 27 16:14:03 2003
@@ -167,7 +167,7 @@
     }
     $stat{$id}++;
     if (!$count) {
-	print "$1 $id $4\n";
+	print "$1 $id $4 $3\n";
     }
 }