From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-x230.google.com (mail-io0-x230.google.com [IPv6:2607:f8b0:4001:c06::230]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id F37673BA8E for ; Tue, 3 Oct 2017 23:17:13 -0400 (EDT) Received: by mail-io0-x230.google.com with SMTP id l15so9389221iol.8 for ; Tue, 03 Oct 2017 20:17:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-transfer-encoding:content-language; bh=MCzhgYpnlpu/3dovKg1IcLkcT/F8Oa+xvWTHfV01qyE=; b=XgFFm3RtirDxrPsqruPdtHCou/zjosbnD/QsV8TdOcNRx/5nZOG2iXULbniMUjZXP+ QHtgK9F8FON4hDJpnA5i2QhuRwaL2wkgnBJ2mRTm9k+/kJVYiWLmtMoq/7uSWnaqfCMt qJ8lx7qYrLToBGqPFskib26g1vCqARF07lO8pJ9Ea5P7CkxLQp1T7cKKRha8QUlHdzkg 2K1x0BeVlqXaWShHm0NFJ7fakYP2/Ekuv1ti6oaPpyyvTp/AH5jVqEIvYOfFqdaX9RzY U3a+xc7eBMPzGiPZGyCg2u+1ceLZNDUEOK+OYWDYfCuymAAlNT5SxyObQzawYfmaubBG rVlg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=MCzhgYpnlpu/3dovKg1IcLkcT/F8Oa+xvWTHfV01qyE=; b=hmZL3IxCi70u1EA3iYuL3x4vIAt3ADsC1Nt12VdwAw2P8CoeH+r5Ae+gUJN46RV6ig JAR3l1Ph7Nsf67A5kjADcELj5ZeMRsta9Pkt82mlojZQV7HSKrZAzy3qBKpjvT3FAYe6 xRZDmDGgnialiKkqHawrZGn5s7+wQTPKu34iqH7YQBJiS31FglchilBFj0uE013rBSxW DWup3KkVDGknfX+Olw1AIrWpfWgQYEHKsemWAvMp73ZoEPEC20ylClMr64Mli9h7epoO NlhlS0xMzQOnny1QhS2ISgm+YqC9/FEfVV4p4Q+1SU2H9dt8nliMleYSdtOdYrZx3eKh u3Gg== X-Gm-Message-State: AMCzsaUg2t4Zf5r1HAIqvijl2L+QkL1zcSQDANchWQdjXVhuLNLYKCpX G0xCUp1V/4gOorEfIse1apbBDNqu X-Google-Smtp-Source: AOwi7QC/2Nbx0WTosypG6cLMDF6g65eP9DA5ZwTgHIkGxJUd+290N54ejdhjM1oWyreg3WkOCubJ4w== X-Received: by 10.107.157.129 with SMTP id g123mr32750113ioe.182.1507087033041; Tue, 03 Oct 2017 20:17:13 -0700 (PDT) Received: from [10.0.4.10] (96-84-81-161-static.hfc.comcastbusiness.net. [96.84.81.161]) by smtp.gmail.com with ESMTPSA id m7sm418022ita.2.2017.10.03.20.17.12 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 03 Oct 2017 20:17:12 -0700 (PDT) To: cake@lists.bufferbloat.net References: From: Noah Causin Message-ID: <198aa7d2-246d-40c2-fd46-89979fa249d4@gmail.com> Date: Tue, 3 Oct 2017 22:17:12 -0500 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Subject: Re: [Cake] best way at getting at tcp ack data? X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 04 Oct 2017 03:17:14 -0000 After reading about ACK filtering, I have an idea and wonder if it is possible.  I only have basic knowledge about the TCP protocol. Instead of dropping TCP data packets, would it be possible to drop normal ACK packets to signal congestion? The sender would see that ACK packets are missing and slow down its transmission rate and re-transmit the data packets it thought were lost.  Since the client has already received the packets beforehand, the application would not experience packet loss, and TCP would simply re-acknowledge the packets and discard the copies. Could this be used to create a pseudo-lossless congestion notification scheme, since the client would not see any packet loss, which could be beneficial for certain applications? Noah