On Thursday 15 May 2003 19:41, Varun Varma wrote: > Stef Coene wrote: > > You mean something like the gred or red qdisc. > > The difference is RED drops the packets after they arrive basing it on > the understanding that the TCP implementations would take this as a hint > and slow down the transmission rates. > > Rate control on the other hand takes a more "hands on" approach to the > problem. As Jose mentioned, ack pacing, window sizing etc...it actually > exploits fundamentals in TCP flow control itself. > > > But I wonder if it will be a big different between "TCP rate contorl" and > > plain old shaping. > > There are lot of comparisions on this. I don't want to get into a debate > here, since people from each group [rate control vs. queueing] feel > very stongly about their stand. But I'm still intested in the comparision :) > Simply put, there are dozens of queueing disciplines, because some might > "behave better" than other in some cases. I *feel* that rate control > would work better in some particular cases, so I was interested in > knowing if a rate control like implementation is available under Linux. Not in the default linux kernel. > >>Seems to be a patented "idea" in the USA, but I remember someone on this > >>list talked not long ago about he waaas implementing something like this > >>for Linux, from outside the USA. Check the archives for the message: > >>Subject: Re: [LARTC] How far can TC go? > >>From: Patrick McHardy <kaber@xxxxxxxxx> > >>Date: Sat, 29 Mar 2003 11:08:30 +0100 > > Thanks for the reference...still need to check it out. I already did : Packeteer has various patents covering tcp rate control and everything else they do, including the "idea" to look at upper layers to detect the type of traffic. I live in germany so i don't really care that much about their patents (they had none in europe last time i checked). last summer i started implementing tcp rate control as qdisc for linux. i haven't worked on it for a couple of month now, but if anyone wishes to participate i would be glad to dig out my source again. it is basically working, the remaining problems are mostly how to detect and handle interactive traffic. Patrick > About the patent thing...I know for sure that ack pacing has been > published in paper before. Note: I am not suggesting how to circumvent > this patent in any way. That said, I think it should be possible to work > out other mechanisms, based around TCP flow control, which don't work > the way Packeteer's patent works. > > If you google for "linux rate control", you come up with a link like: > > http://www.postel.org/pipermail/end2end-interest/2001-April/000701.html > > Which is a master's thesis, proposing another way to implement rate > control. Stef -- stef.coene@xxxxxxxxx "Using Linux as bandwidth manager" http://www.docum.org/ #lartc @ irc.oftc.net
