diff --git a/tcpdump_tools/tcpdump_sum.pl b/tcpdump_tools/tcpdump_sum.pl
new file mode 100755
index 0000000..cf7d6fb
--- /dev/null
+++ b/tcpdump_tools/tcpdump_sum.pl
@@ -0,0 +1,39 @@
+#!/usr/bin/perl
+
+# print summary of tcpdump output
+
+sub dumpstats {
+    print "-" x 60, "\n";
+    print "$time\n";
+    for $i (sort { $sum{$a} <=> $sum{$b} } keys (%sum)) {
+	printf("\t%6d %s\n", $sum{$i}, $i);
+    }
+}
+
+while (<>) {
+    if (m/^(\d\d:\d\d):\d\d\.\d{6} ([-\w\.]+) \> ([-\w\.]+): (.*)/) {
+	$time = $1;
+	$from = $2;
+	$to = $3;
+	$rest = $4;
+	if ($time ne $time_last) {
+	    dumpstats();
+	    undef %sum;
+	    $time_last = $time;
+	}
+	if ($rest =~ m/^. (\d+):(\d+)\((\d+)\)/) {
+	    # tcp
+	    $sum{$from . " > " . $to} += $3;
+	} elsif ($rest =~ m/^. ack (\d+) win (\d+) \(DF\)/) {
+	    # tcp ack 
+	    $sum{$from . " > " . $to} += 0;
+	} else {
+	    print stderr "unparseable2: $_";
+	}
+	    
+	    
+    } else {
+	print stderr "unparseable1: $_";
+    }
+}
+dumpstats();