Andy Furniss schrieb: > Daniel Schaffrath wrote: >> Dear Community, >> >> sorry for the somewhat dumb question. Maybe someone has any >> pointer to how to setup the RED queue to mark pakets with ECN. In >> particular what are appropriate parameter settings for limit, >> min, max, etc. > > I have never really played with red - but I wouldn't start by > putting it on lo - I don't think you will get a backlog. Even on > root of an eth there will be quite big buffer to fill before it > gets any backlog. Could you explain this a bit more in detail, why does it not work on root of an device? I tried it with various configurations and indeed it does not work. Even if the incoming interface is much faster then the outgoing interface I can't get the red queue to drop or mark packets. Packets are always dropped somewhere else? > > You are best using it as a child of something that rate limits > tbf/hfsc/htb. There is a rate parameter which I guess you should > use - but it's not to actually do the rate limiting. Thanks for the hint! It seems to work that way, I used this: tc qdisc add dev wifi0 root handle 1 tbf rate 36mbit burst 5kb latency 100ms peakrate 54mbit minburst 1540 tc qdisc add dev wifi0 parent 1: red limit 10000 min 2000 max 5000 avpkt 1000 burst 2 probability .2 ecn Then suddenly i get marked packets: qdisc red 8003: dev wifi0 parent 1: limit 10000b min 2000b max 5000b ecn Sent 5913561 bytes 3938 pkt (dropped 0, overlimits 6 requeues 2611) rate 0bit 0pps backlog 0b 0p requeues 2611 marked 6 early 0 pdrop 0 other 0 But question remains: Why does it not work with root qdisc? And 6 packets are still a bit few? Ingoing interface is 100 mbit, outgoing link on wifi0 is about 5 mbit... > As for ECN, it's off by default on Linux, so I don't think it will > be much use unless you have control over the network. I just turned > it on on two of my PCs - > > echo 1 > /proc/sys/net/ipv4/tcp_ecn > > and did a test with red and it does work and save some drops. Could you show your configuration or is it too complex? How many packets got marked? Thank you. Best regards, Arnd _______________________________________________ LARTC mailing list LARTC@xxxxxxxxxxxxxxx http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc
