From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-03-ewr.dyndns.com (mxout-133-ewr.mailhop.org [216.146.33.133]) by lists.bufferbloat.net (Postfix) with ESMTP id ECDBD2E03C0 for ; Wed, 16 Mar 2011 16:23:15 -0700 (PDT) Received: from scan-02-ewr.mailhop.org (scan-02-ewr.local [10.0.141.224]) by mail-03-ewr.dyndns.com (Postfix) with ESMTP id 51A5E786728 for ; Wed, 16 Mar 2011 23:23:15 +0000 (UTC) X-Spam-Score: -1.0 (-) X-Mail-Handler: MailHop by DynDNS X-Originating-IP: 74.125.82.47 Received: from mail-ww0-f47.google.com (mail-ww0-f47.google.com [74.125.82.47]) by mail-03-ewr.dyndns.com (Postfix) with ESMTP id D61897865BE for ; Wed, 16 Mar 2011 23:23:14 +0000 (UTC) Received: by wwk4 with SMTP id 4so2353995wwk.28 for ; Wed, 16 Mar 2011 16:23:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:subject:mime-version:content-type:from :in-reply-to:date:cc:content-transfer-encoding:message-id:references :to:x-mailer; bh=D8OW3uxqpZF9THg5myUE9zBmFpBDB3zoBXzJkcLuPHc=; b=mA/uDPP44rRXxzO/e3q11+nbQKR/BPo3BzVj7y6wzKBjoADCa2dehGb0a3SA6leUHS ysfDVrzsIMXzz3jHXL12saJKRwv7BaF4NQIVynjQYxq0/2A58n5Gp1KEfu2UYBWK8URq RwkzerBzxSoSIf48lbuQirzAY3cbh1/kOW8rg= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:mime-version:content-type:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to:x-mailer; b=Q0Kw2uucCynhMbpLcU7MoJD8/kYdejVvu0+aAHLcFJWCDDvQEszbHaMchP5o5s/O64 c0sRmTuemj4cNx10NnJka48vS58OtTybEGsI3AMvXZTFSPaGsBmBDpwtwsGLKXVEm2Cq VTMnblwwveCluoOIepo9YUtJ+s3fWyZajmbmg= Received: by 10.216.55.145 with SMTP id k17mr64084wec.48.1300317793986; Wed, 16 Mar 2011 16:23:13 -0700 (PDT) Received: from [192.168.239.42] (xdsl-83-150-84-172.nebulazone.fi [83.150.84.172]) by mx.google.com with ESMTPS id h19sm258971wbc.58.2011.03.16.16.23.13 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 16 Mar 2011 16:23:13 -0700 (PDT) Mime-Version: 1.0 (Apple Message framework v1082) Content-Type: text/plain; charset=us-ascii From: Jonathan Morton In-Reply-To: <0D064802-2668-4FB7-A0BB-8F717DD4CAF8@cisco.com> Date: Thu, 17 Mar 2011 01:23:11 +0200 Content-Transfer-Encoding: quoted-printable Message-Id: <9DB38C10-12C6-4B08-B038-16B9437FAE57@gmail.com> References: <4D7F4121.40307@freedesktop.org> <580BEA5E3B99744AB1F5BFF5E9A3C67D01708ED2A4@HE111648.emea1.cds.t-internal.com> <0D064802-2668-4FB7-A0BB-8F717DD4CAF8@cisco.com> To: Fred Baker X-Mailer: Apple Mail (2.1082) Cc: bloat@lists.bufferbloat.net 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 23:23:16 -0000 On 17 Mar, 2011, at 12:48 am, Fred Baker wrote: >> 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 791, a router that buffers a packet by n seconds must decrease = its TTL by n. I doubt that many routers implement this properly. >=20 > There is, of course, a fundamental bug in that, noted in RFC 970. >=20 > RFC 1812, which I edited, contains this text (that I didn't write): >=20 > In this specification, we have reluctantly decided to follow the > strong belief among the router vendors that the time limit > function should be optional. The major problem with the original TTL spec was that a router generally = doesn't keep a packet for an integer number of seconds (at least, not in = anything but the most ancient of hardware). If three separate routers = each buffer for 350ms, that's about 1 second elapsed, but there is no = way for the routers to indicate this to each other. Yet the TTL field = was an integer number of seconds. The later hop-count spec is much saner. - Jonathan