From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sj-iport-2.cisco.com (sj-iport-2.cisco.com [171.71.176.71]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "sj-iport-2.cisco.com", Issuer "Cisco SSCA" (not verified)) by huchra.bufferbloat.net (Postfix) with ESMTPS id D2EF7201AFA for ; Fri, 6 May 2011 14:51:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=fred@cisco.com; l=1219; q=dns/txt; s=iport; t=1304718992; x=1305928592; h=subject:mime-version:from:in-reply-to:date:cc:message-id: references:to:content-transfer-encoding; bh=dy/GPcE1cPUIw75ouAvMaqCjP93HFrSta13riTR6R7M=; b=PgfcU2IUcW8uarKWGsdS9t+c7JyjMlvkIKzVzYTQO3vwAwQRDwwIlXaW 4wjohzwmEsVSXAf6BT+FeGFGF7I3UMehHJziXlXTxe7P8rT6tZ3XxoZcI YZPbqsJBBNfEQrF4RfEn6o4PPKNVdna3g+sze15hGd7Y6PF9uQgf1vbyi c=; X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AvsEAKBtxE2rRDoI/2dsb2JhbACmHneIcZ8hnXGGCQSGPYkbhCSKUA X-IronPort-AV: E=Sophos;i="4.64,328,1301875200"; d="scan'208";a="352106180" Received: from mtv-core-3.cisco.com ([171.68.58.8]) by sj-iport-2.cisco.com with ESMTP; 06 May 2011 21:56:22 +0000 Received: from stealth-10-32-244-222.cisco.com (stealth-10-32-244-222.cisco.com [10.32.244.222]) by mtv-core-3.cisco.com (8.14.3/8.14.3) with ESMTP id p46LuHl7014607; Fri, 6 May 2011 21:56:22 GMT Received: from [127.0.0.1] by stealth-10-32-244-222.cisco.com (PGP Universal service); Fri, 06 May 2011 14:56:22 -0700 X-PGP-Universal: processed; by stealth-10-32-244-222.cisco.com on Fri, 06 May 2011 14:56:22 -0700 Mime-Version: 1.0 (Apple Message framework v1084) From: Fred Baker In-Reply-To: <1304694852.29492.16.camel@amd.pacdat.net> Date: Fri, 6 May 2011 14:56:01 -0700 Message-Id: References: <4DB70FDA.6000507@mti-systems.com> <4DC2C9D2.8040703@freedesktop.org> <1EA9A6B3-F1D0-435C-8029-43756D53D8FD@gmail.com> <1304694852.29492.16.camel@amd.pacdat.net> To: richard X-Mailer: Apple Mail (2.1084) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Cc: bloat@lists.bufferbloat.net Subject: Re: [Bloat] Goodput fraction w/ AQM vs bufferbloat 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: Fri, 06 May 2011 21:51:26 -0000 On May 6, 2011, at 8:14 AM, richard wrote: > If every packet takes two attempts then the ratio will be 1/2 - 1 unit > of googput for two units of throughput (at least up to the = choke-point). > This is worst-case, so the ratio is likely to be something better than > that 3/4, 5/6, 99/100 ???=20 I have a suggestion. turn on tcpdump on your laptop. Download a web page = with lots of imagines, such as a google images web page, and then = download a humongous file. Scan through the output file for SACK = messages; that will give you the places where the receiver (you) saw = losses and tried to recover from them. > Putting a number to this will also help those of us trying to get ISPs > to understand that their Usage Based Bilking (UBB) won't address the > real problem which is hidden in this ratio. The fact is, the choke = point > for much of this is the home router/firewall - and so that 1/2 ratio > tells me the consumer is getting hosed for a technical problem. I think you need to do some research there. A TCP session with 1% loss = (your ratio being 1/100) has difficulty maintaining throughput; usual = TCP loss rates are on the order of tenths to hundredths of a percent.=