Use better RED parameters

Use recommendations from Sally Floyd.

3 files changed, 17 insertions, 15 deletions

diff --git a/lib/Vyatta/Qos/ShaperClass.pm b/lib/Vyatta/Qos/ShaperClass.pm
index d89dfb9..c3fae16 100644
--- a/lib/Vyatta/Qos/ShaperClass.pm
+++ b/lib/Vyatta/Qos/ShaperClass.pm
@@ -151,16 +151,13 @@ sub fifoQdisc {
 
 # Red is has way to many configuration options
 # make some assumptions to make this sane (based on LARTC)
-#   average size := 1000 bytes
-#   limit        := queue-limit * average
-#   max          := limit / 8
-#   min          := max / 3
-#   burst        := (2 * min + max) / (3 * average)
+#   average size = 1000 bytes
+#   latency      = 100ms
 sub redQdisc {
     my ( $self, $dev, $rate ) = @_;
     my $avg = 1000;
-    my $latency = 100000;	# 100 ms
-    my ($qmin, $qmax, $burst) = RedParam($rate, $latency, $avg);
+    my $latency = 100000;
+    my ($qmin, $qmax, $burst, $maxp) = RedParam($rate, $latency, $avg);
 
     my $limit = $self->{_limit};
     my $qlimit;
@@ -171,7 +168,8 @@ sub redQdisc {
     }
 
     printf "red limit %d min %d max %d avpkt %d", $qlimit, $qmin, $qmax, $avg;
-    printf " burst %d probability 0.02 bandwidth %d ecn\n", $burst, $rate / 1000;
+    printf " burst %d probability %f bandwidth %d ecn\n", 
+    	$prob, $burst, $maxp, $rate / 1000;
 }
 
 my %qdiscOptions = (
diff --git a/lib/Vyatta/Qos/Util.pm b/lib/Vyatta/Qos/Util.pm
index afd5c78..ee1b722 100644
--- a/lib/Vyatta/Qos/Util.pm
+++ b/lib/Vyatta/Qos/Util.pm
@@ -329,13 +329,16 @@ sub ethtoolRate {
 # Avpkt = Average Packet Length
 # Burst = ( 2 * MinThreshold + MaxThreshold) / ( 3 * Avpkt )
 # Limit = 4 * MaxThreshold
+#
+# These are based on Sally Floyd's recommendations:
+#  http://www.icir.org/floyd/REDparameters.txt
 sub RedParam {
     my ( $bandwidth, $latency, $avgpkt ) = @_;
     my $qmax = ( $bandwidth * $latency ) / 8000000;
     my $qmin = $qmax / 3;
     my $burst = ( 2 * $qmin + $qmax ) / ( 3 * $avgpkt );
 
-    return ($qmin, $qmax, $burst);
+    return ($qmin, $qmax, $burst, 0.1);
 }
 
 1;
diff --git a/lib/Vyatta/Qos/WeightedRandom.pm b/lib/Vyatta/Qos/WeightedRandom.pm
index 99f9b9e..0b1dc37 100644
--- a/lib/Vyatta/Qos/WeightedRandom.pm
+++ b/lib/Vyatta/Qos/WeightedRandom.pm
@@ -102,7 +102,7 @@ sub commands {
 
     # fill in id of default
     $default->{id} = ++$maxid;
-    unshift @$classes, $default;
+    push @$classes, $default;
 
     print "qdisc add dev $dev handle 1: root gred";
     printf " setup DPs %d default %d\n", $maxid+1, $maxid;
@@ -112,15 +112,16 @@ sub commands {
         my $avg     = $class->{_avgpkt};
         my $latency = getTime( $class->{_latency} );
 
-        my ( $qmin, $qmax, $burst ) = RedParam( $classbw, $latency, $avg );
+        my ( $qmin, $qmax, $burst, $maxp )
+	    = RedParam( $classbw, $latency, $avg );
 
         print "qdisc change dev $dev root gred";
-        printf " limit %d min %d max %d avpkt %d", 
-		4 * $qmax, $qmin, $qmax, $avg;
+	printf " prio %d", $class->{_priority} if $class->{_priority};
+        printf " limit %d min %d max %d avpkt %d probability %f", 
+		4 * $qmax, $qmin, $qmax, $avg, $maxp;
         printf " burst %d bandwidth %d DP %d",
 		$burst, $rate, $class->{id};
-	printf " prio %d", $class->{_priority} if $class->{_priority};
-	print " probability 0.02\n";
+	print " probability 0.1\n";
 
         foreach my $match ( $class->matchRules() ) {
             $match->filter( $dev, 1, $class->{_priority} );