From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Furniss Date: Mon, 17 May 2004 23:19:40 +0000 Subject: Re: [LARTC] 2 Questions on filtering incoming stuff Message-Id: <40A9488C.1040505@dsl.pipex.com> List-Id: References: <40A92F1A.4030706@wildgooses.com> In-Reply-To: <40A92F1A.4030706@wildgooses.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lartc@vger.kernel.org Ed Wildgoose wrote: > Two easy questions after having read the LARTC HOWTO document (which by > the way is a *fantastic* document. Congratulations to all who > contributed!) > > First is: Can I prioritise my "drops" on incoming traffic when the link > is overloaded. ie instead of just tail dropping, can I "prefer" to drop > certain classes of traffic? Yes - you would queue before dropping. If so, do I do this by setting up, say, a > HTB tree like on the incoming, but the only action at the leaf is to drop? > You attach a queue to the leaf, which may drop. > Second: Theoretically now.... There appears to be no way to tweak > "window length" to throttle incoming data... But in theory, would a > module which delayed the outgoing ACK's have the same effect? Queueing has much the same effect. Obviously > this module would need some sort of packet accounting ffrom the incoming > interface in order to supply the outgoing filter with the info it needed > (not even sure if this design makes it hard to implement such a > thing?). Fast and selective acks and timeouts, obviously make this very > hard to implement as well... > Throttling by rwin manipulation would be nice - but complicated. > However, the main point is that I don't really understand the process by > which linux (and other OSs) discover the steady state speed of a link? > Anyone got a good pointer to how "slow start" and "fast start" work, and > how it adjusts speed through time? It's tcp that finds the limits. There are many docs out there like www.jessingale.dsl.pipex.com/tcp-noureddine02transmission.pdf Andy. _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/