From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-13-ewr.dyndns.com (mxout-064-ewr.mailhop.org [216.146.33.64]) by lists.bufferbloat.net (Postfix) with ESMTP id A35EB2E04A9 for ; Wed, 16 Mar 2011 02:05:26 -0700 (PDT) Received: from scan-12-ewr.mailhop.org (scan-12-ewr.local [10.0.141.230]) by mail-13-ewr.dyndns.com (Postfix) with ESMTP id DFCDDA4C0E1 for ; Wed, 16 Mar 2011 09:05:25 +0000 (UTC) X-Spam-Score: -1.0 (-) X-Mail-Handler: MailHop by DynDNS X-Originating-IP: 217.243.239.135 Received: from tcmail73.telekom.de (tcmail73.telekom.de [217.243.239.135]) by mail-13-ewr.dyndns.com (Postfix) with ESMTP id 5A5E1A4C0D2 for ; Wed, 16 Mar 2011 09:05:25 +0000 (UTC) Received: from he111629.emea1.cds.t-internal.com ([10.134.93.21]) by tcmail71.telekom.de with ESMTP/TLS/AES128-SHA; 16 Mar 2011 10:04:50 +0100 Received: from HE111648.emea1.cds.t-internal.com ([169.254.5.70]) by HE111629.emea1.cds.t-internal.com ([::1]) with mapi; Wed, 16 Mar 2011 10:04:50 +0100 From: To: Date: Wed, 16 Mar 2011 10:04:48 +0100 Thread-Topic: [Bloat] Random idea in reaction to all the discussion of TCP flavours - timestamps? Thread-Index: Acvi/Ouc6lakAVa8RMeO1MFASjOkJQAuuX4A Message-ID: <580BEA5E3B99744AB1F5BFF5E9A3C67D01708ED2A4@HE111648.emea1.cds.t-internal.com> References: <4D7F4121.40307@freedesktop.org> In-Reply-To: <4D7F4121.40307@freedesktop.org> Accept-Language: en-US, de-DE Content-Language: de-DE X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US, de-DE Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [Bloat] Random idea in reaction to all the discussion of TCP flavours - timestamps? X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 16 Mar 2011 09:05:26 -0000 Jim Wrote: > Back last summer, to my surprise, when I asked Van Jacobson about my > traces, he said all the required proof was already present in my traces, > since modern Linux (and I presume other) operating systems had time > stamps in them (the TCP timestamps option). > > Here's the off the wall idea. The buffers we observe are often many > times (orders of magnitude) larger than any rational RTT. > > So the question I have is whether there is some technique whereby > monitoring the timestamps that may already be present in the traffic > (and knowing what "sane" RTT's are) that we can start marking traffic in > time prevent the worst effects of bloating buffers? This reminds me of a related concept, using the TTL really as 'Time To Live= ' (in today's IP, it's more of a 'Remaining Hop Count). According to RfC 79= 1, a router that buffers a packet by n seconds must decrease its TTL by n. = I doubt that many routers implement this properly. Wolfgang _______________________________________________ Bloat mailing list Bloat@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/bloat