From owner-freebsd-isp Mon Apr 6 15:15:44 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id PAA22992 for freebsd-isp-outgoing; Mon, 6 Apr 1998 15:15:44 -0700 (PDT) (envelope-from owner-freebsd-isp@FreeBSD.ORG) Received: from mail.keyworld.net (root@mail.keyworld.net [194.21.164.2]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id PAA22972 for ; Mon, 6 Apr 1998 15:15:39 -0700 (PDT) (envelope-from chrism@keyworld.net) Received: from chrism (ppp71.keyworld.net [194.21.164.134]) by mail.keyworld.net (8.8.5/8.8.4) with ESMTP id AAA31285; Tue, 7 Apr 1998 00:10:45 +0200 Message-Id: <199804062210.AAA31285@mail.keyworld.net> From: "Christopher Martin at Home" To: "Glen Foster" Cc: , , Subject: Re: Bandwidth limiter for services? Date: Tue, 7 Apr 1998 00:10:07 +0200 X-MSMail-Priority: Normal X-Priority: 3 X-Mailer: Microsoft Internet Mail 4.70.1155 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-freebsd-isp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > > 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 > I wish he would too. -- Christopher Martin BDM -KeyWORLD http://www.keyworld.net ---------- > From: Glen Foster > 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 > > >From: "Christopher Martin at Home" > >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