Date: Mon, 05 Oct 2009 10:27:16 -0700 From: Julian Elischer <julian@elischer.org> To: rihad <rihad@mail.ru> Cc: freebsd-net@freebsd.org, Eugene Grosbein <eugen@kuzbass.ru> Subject: Re: dummynet dropping too many packets Message-ID: <4ACA2C74.9030206@elischer.org> In-Reply-To: <4AC9E415.9040801@mail.ru> References: <20091005061025.GB55845@onelab2.iet.unipi.it> <4AC9B400.9020400@mail.ru> <20091005090102.GA70430@svzserv.kemerovo.su> <4AC9BC5A.50902@mail.ru> <20091005095600.GA73335@svzserv.kemerovo.su> <20091005100446.GA60244@onelab2.iet.unipi.it> <20091005100532.GC73335@svzserv.kemerovo.su> <4AC9C88A.5050509@mail.ru> <20091005113037.GA77999@svzserv.kemerovo.su> <4AC9DD72.9060802@mail.ru> <20091005120057.GA79942@svzserv.kemerovo.su> <4AC9E415.9040801@mail.ru>
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rihad wrote: > Eugene Grosbein wrote: >> On Mon, Oct 05, 2009 at 04:50:10PM +0500, rihad wrote: >> >>>>> Where has TCP slow-start gone? My router box isn't some application >>>>> proxy that starts downloading at full 100 mbit/s thus quickly >>>>> filling client's 1 mbit/s link. It's just a router. >>>> While there is no or little competition for bandwidth from the router >>>> to clients, TCP would work just fine. I suspect your shaping policy >>>> makes heavy competition between clients. In this case, TCP behaves >>>> not-so-well without help of router's good shaping algorythms >>>> and taildrop is not good one. >>>> >>> Nothing fancy (i.e. no competition). Only tons of per-user pipes >>> simulating the given throughput. >> >> You've mentioned previously: "The pipes are fine, each normally having >> 100-120 concurrent consumers (i.e. active users)." >> This IS competition between TCP flows inside each pipe. >> > Well, each user gets instantiated with a new copy of the pipe. Each such > user counts towards the limit imposed by hash_size*max_chain_len for > that pipe only. It would have been competition had I used dst-ip dst-ip > 0xffffff00 or similar and not dst-ip 0xffffffff, _then_ all 256 users > (determined by the mask) would compete for the pipe's bandwidth. So the > only competition is in the uplink at our main Cisco, I guess. yesssss, so try running your interfaces slower. :-) > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org"
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