From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Furniss Date: Mon, 19 Apr 2004 21:08:02 +0000 Subject: Re: [LARTC] Making tcp start transfers slow Message-Id: <40843FB2.80503@dsl.pipex.com> List-Id: References: <20040415122135.9743.LARTC@schmakk.dk> In-Reply-To: <20040415122135.9743.LARTC@schmakk.dk> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lartc@vger.kernel.org Roy wrote: > I just had one idea, about this. > > what if make iptables module which will make something like enlarged copy > of syn packet and send it back to the sender? > (another option would be to kill 1 or 2 ack packets for one syn packet this > whould force server to reduce speed) > > > that way htb could count upcoming packet and prepare by reducing other > connetions speed? > of course that synthetic packet will have higest possible priority since it > supposed to be appear in future so cant be shaped anyway > I don't really get this :-) > > I will try to add this functionality to my imq module next week probably. > ------------------------ > connbytes solution is not good for this, it slows down small picture loading > in web pages very much, and big downloads get even more "unused" bandwitch. > so effect is not good. expecialy that looks bad on network, when pages > become incredibly slow, but big downloads fast. Depends on lots of things I suppose - the way I have it set new connections get 256kbit - not that bad for browsing. ISTR seeing one of your scripts that did similar, IIRC using sfq with low rates. I don't quite do it like that - for a start sfq 128 queue length is too much and if you use it on ingress sfq will hash the ~4 simoultaneous connections your browser makes into one slot. I guess yours simulated a drop with the reordering when they swapped queues rather than really dropping with a short queue to get out of slowstart. SFQ causes instability every time it rehashes on ingress because of this - there is a todo in the code somewhere. I like to set perturb high. This ingress shaping with stuff made for egress is a bit tricky - but it can be tweaked a bit. Andy. _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/