From e61df2105cb0cb936bb4298b6139544ca1bfa62a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 24 Jan 2012 14:18:33 +0100 Subject: [PATCH] tc-red: update man page include documentation for harddrop and adaptive parameters. All parameters but limit and avpkt are optional. Signed-off-by: Eric Dumazet --- man/man8/tc-red.8 | 52 +++++++++++++++++++++++++++++++++++++---------- 1 file changed, 41 insertions(+), 11 deletions(-) diff --git a/man/man8/tc-red.8 b/man/man8/tc-red.8 index 32a47b892..f410d157e 100644 --- a/man/man8/tc-red.8 +++ b/man/man8/tc-red.8 @@ -5,18 +5,19 @@ red \- Random Early Detection .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 @@ -66,7 +67,10 @@ parameter is provided to set a hard maximum for the size of the queue. .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 @@ -74,11 +78,14 @@ least twice .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 @@ -99,7 +106,7 @@ average queue size calculations. 1000 is a good value. 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 @@ -109,7 +116,26 @@ dropping a packet. If this parameter is specified, packets which indicate 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), @@ -123,10 +149,14 @@ Congestion Avoidance. http://www.aciri.org/floyd/papers/red/red.html .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, , Alexey Makarenko -, J Hadi Salim . +, J Hadi Salim , +Eric Dumazet . This manpage maintained by bert hubert -- 2.47.3