Date: Tue, 7 Apr 1998 00:10:07 +0200 From: "Christopher Martin at Home" <chrism@keyworld.net> To: "Glen Foster" <gfoster@gfoster.com> Cc: <Anthony.Barlow@europe.simoco.com>, <freebsd-isp@FreeBSD.ORG>, <freebsd@plinet.com> Subject: Re: Bandwidth limiter for services? Message-ID: <199804062210.AAA31285@mail.keyworld.net>
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> > This is speculation on my part based on scanty evidence. I wish > Dennis would 'fess up and describe the logic behind his code in this > forum. > > Glen Foster <gfoster@gfoster.com> > I wish he would too. -- Christopher Martin BDM -KeyWORLD http://www.keyworld.net ---------- > From: Glen Foster <gfoster@gfoster.com> > To: chrism@keyworld.net > Cc: Anthony.Barlow@europe.simoco.com; freebsd-isp@FreeBSD.ORG; freebsd@plinet.com > Subject: Re: Bandwidth limiter for services? > Date: Monday, April 06, 1998 11:52 PM > > Is this really the case? Dennis has been reluctant to describe the > mechanism of his bandwidth manager but hints he has dropped on this > and other FreeBSD lists indicate that they use a "strategically-timed > ACK delay" mechanism to limit bandwidth rather than dropping packets. > Basically, they ack as fast as the bandwidth limit allows given the > size of the associated queue. > > Obviously, this adds a little or a lot of latency, more when the > bandwidth limit is approaching, but this is not unlike the way a > partially-meshed network "looks" to a sender as it approachs > saturation and it conserves aggregate bandwidth better than an > aggressive discard strategy does (at least as long as the ACK delay is > shorter than the retransmission timeout). > > This is speculation on my part based on scanty evidence. I wish > Dennis would 'fess up and describe the logic behind his code in this > forum. > > Glen Foster <gfoster@gfoster.com> > > >From: "Christopher Martin at Home" <chrism@keyworld.net> > >Date: Mon, 6 Apr 1998 23:08:02 +0200 > > > >I suggest that you check it out though. I think it works by dropping > >packets. If it does the pipe might be filled by stuff that is already > >downloaded. This might result in unaccepttable amount of retransmissions > >from source. > > > >So you would not be really saving bandwidth... > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-isp" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message
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