From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-12-ewr.dyndns.com (mxout-079-ewr.mailhop.org [216.146.33.79]) by lists.bufferbloat.net (Postfix) with ESMTP id 075072E0271 for ; Tue, 15 Mar 2011 19:23:51 -0700 (PDT) Received: from scan-11-ewr.mailhop.org (scan-11-ewr.local [10.0.141.229]) by mail-12-ewr.dyndns.com (Postfix) with ESMTP id E04C793058E for ; Wed, 16 Mar 2011 02:23:50 +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-12-ewr.dyndns.com (Postfix) with ESMTP id 6A232930464 for ; Wed, 16 Mar 2011 02:23:50 +0000 (UTC) Received: by wwk4 with SMTP id 4so1302131wwk.28 for ; Tue, 15 Mar 2011 19:23:49 -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=y6qOtVlSZpoWI3XlfEpU0AjSYWg88R/rRNcwtTnbdzY=; b=WWYI/DEm7uzqbUPeQc2+GM4Oj8WBi6swFXJjWeKLUI1XBZ+11NnDh0+gIgL4KJPVdd 7+R5t9KRetkv84T86M3YEKTJMmcmjAeHGatvx9/QzRy0MSHWuG1PMqu6H+z36ldzXoO2 ziTAT9k58t9D78cBLVMUBeBCaFdq0asWh+DA4= 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=lzioNaOVkqq0yoiMhpmrURb8lK7EQwkIiMHh2+loTuFsf6Q4zxqPqY1VKr+Y5fEYZT RKF78NhKqzuo5nsEy+VBnv14pPmeU/fLjssD1zEg4zD+J24NH/pEBn7jR6naekBST40C t9OHICIqYnLWlxbUonuuEbWCeZ5li0jgeEaxE= Received: by 10.216.136.67 with SMTP id v45mr4364013wei.106.1300242229643; Tue, 15 Mar 2011 19:23:49 -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 u9sm518349wbg.6.2011.03.15.19.23.48 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 15 Mar 2011 19:23:49 -0700 (PDT) Mime-Version: 1.0 (Apple Message framework v1082) Content-Type: text/plain; charset=iso-8859-1 From: Jonathan Morton In-Reply-To: <87bp1b4yh4.fsf@cruithne.co.teklibre.org> Date: Wed, 16 Mar 2011 04:23:46 +0200 Content-Transfer-Encoding: quoted-printable Message-Id: <35010A85-C5A4-4133-8707-4E114C65A8C6@gmail.com> References: <4D7F4121.40307@freedesktop.org> <20110315175942.GA10064@goldfish> <1300212877.2087.2155.camel@tardy> <20110315183111.GB2542@tuxdriver.com> <29B06777-CC5F-4802-8727-B04F58CDA9E3@gmail.com> <20110315205146.GF2542@tuxdriver.com> <219C7840-ED79-49EA-929D-96C5A6200401@gmail.com> <20110315151946.31e86b46@nehalam> <1300228592.2087.2191.camel@tardy> <1300229578.2565.29.camel@edumazet-laptop> <87fwqo54n7.fsf@cruithne.co.teklibre.org> <823E2A7B-4F46-4159-8029-BD3B075CC4CE@gmail.com> <87bp1b6fo0.fsf@cruithne.co.teklibre.org> <87bp1b4yh4.fsf@cruithne.co.teklibre.org> To: d@taht.net (=?iso-8859-1?Q?Dave_T=E4ht?=) X-Mailer: Apple Mail (2.1082) Cc: Stephen Hemminger , bloat 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 02:23:52 -0000 On 16 Mar, 2011, at 3:59 am, Dave T=E4ht wrote: > 10 Gig E - 10Gig Switch to 1Gig > | | | | | | | | | | > 1 2 3 4 5 6 7 8 9 0=20 >=20 > And the server connected servicing hundreds of flows. Statistically, > with fair queuing the number of receive buffers required per port will > be close to or equal to 1, where in a primitive FIFO setup, something = > > 10 are required. Well, that's a rather different picture than I had before. I'd hazard a = guess that most good switches can deal with that, but they are switches, = not routers, so latency through them is expected to be even less. With that said, at 10GE speeds you are approaching a megapacket per = second if jumbo frames are not a significant fraction of the traffic. I = think something like SFQ can be made to work at those speeds, but simply = getting the data through the computer that fast is a fairly tough job. = So I agree that if the NIC can do it by itself, so much the better. On the flip side, at a megapacket per second, a thousand-packet buffer = empties in a millisecond. That's less than a disk seek. - Jonathan