.B tc qdisc ... red
.B limit
bytes
-.B min
+.B [ min
bytes
-.B max
+.B ] [ max
bytes
-.B avpkt
+.B ] avpkt
bytes
-.B burst
+.B [ burst
packets
-.B [ ecn ] [ bandwidth
+.B ] [ ecn ] [ harddrop] [ bandwidth
rate
-.B ] probability
+.B ] [ probability
chance
+.B ] [ adaptive ]
.SH DESCRIPTION
Random Early Detection is a classless qdisc which manages its queue size
.SH PARAMETERS
.TP
min
-Average queue size at which marking becomes a possibility.
+Average queue size at which marking becomes a possibility. Defaults to
+.B max
+/3
+
.TP
max
At this average queue size, the marking probability is maximal. Should be at
.B min
to prevent synchronous retransmits, higher for low
.B min.
+Default to
+.B limit
+/4
.TP
probability
Maximum probability for marking, specified as a floating point
number from 0.0 to 1.0. Suggested values are 0.01 or 0.02 (1 or 2%,
-respectively).
+respectively). Default : 0.02
.TP
limit
Hard limit on the real (not average) queue size in bytes. Further packets
bandwidth
This rate is used for calculating the average queue size after some
idle time. Should be set to the bandwidth of your interface. Does not mean
-that RED will shape for you! Optional.
+that RED will shape for you! Optional. Default : 10Mbit
.TP
ecn
As mentioned before, RED can either 'mark' or 'drop'. Explicit Congestion
that their hosts honor ECN will only be marked and not dropped, unless the
queue size hits
.B limit
-bytes. Needs a tc binary with RED support compiled in. Recommended.
+bytes. Recommended.
+.TP
+harddrop
+If average flow queue size is above
+.B max
+bytes, this parameter forces a drop instead of ecn marking.
+.TP
+adaptive
+(Added in linux-3.3) Sets RED in adaptive mode as described in http://icir.org/floyd/papers/adaptiveRed.pdf
+.nf
+Goal of Adaptive RED is to make 'probability' dynamic value between 1% and 50% to reach the target average queue :
+.B (max - min) / 2
+.fi
+
+.SH EXAMPLE
+
+.P
+# tc qdisc add dev eth0 parent 1:1 handle 10: red
+ limit 400000 min 30000 max 90000 avpkt 1000
+ burst 55 ecn adaptive bandwidth 10Mbit
.SH SEE ALSO
.BR tc (8),
.TP
o
Some changes to the algorithm by Alexey N. Kuznetsov.
+.TP
+o
+Adaptive RED : http://icir.org/floyd/papers/adaptiveRed.pdf
.SH AUTHORS
Alexey N. Kuznetsov, <kuznet@ms2.inr.ac.ru>, Alexey Makarenko
-<makar@phoenix.kharkov.ua>, J Hadi Salim <hadi@nortelnetworks.com>.
+<makar@phoenix.kharkov.ua>, J Hadi Salim <hadi@nortelnetworks.com>,
+Eric Dumazet <eric.dumazet@gmail.com>.
This manpage maintained by bert hubert <ahu@ds9a.nl>