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auth=pass (PLAIN) smtp.auth=jgh@wizmail.org Received: from [2a00:b900:109e:0:855c:1404:1b9d:3a94] (helo=lap.dom.ain) by wizmail.org (Exim 4.92.126) (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) with esmtpsa id 1i3LWm-0008WI-Dd for ecn-sane@lists.bufferbloat.net (return-path ); Thu, 29 Aug 2019 14:35:56 +0000 To: ecn-sane@lists.bufferbloat.net References: From: Jeremy Harris Openpgp: preference=signencrypt Autocrypt: addr=jgh@wizmail.org; prefer-encrypt=mutual; keydata= mQENBFWABsQBCADTFfb9EHGGiDel/iFzU0ag1RuoHfL/09z1y7iQlLynOAQTRRNwCWezmqpD p6zDFOf1Ldp0EdEQtUXva5g2lm3o56o+mnXrEQr11uZIcsfGIck7yV/y/17I7ApgXMPg/mcj ifOTM9C7+Ptghf3jUhj4ErYMFQLelBGEZZifnnAoHLOEAH70DENCI08PfYRRG6lZDB09nPW7 vVG8RbRUWjQyxQUWwXuq4gQohSFDqF4NE8zDHE/DgPJ/yFy+wFr2ab90DsE7vOYb42y95keK tTBp98/Y7/2xbzi8EYrXC+291dwZELMHnYLF5sO/fDcrDdwrde2cbZ+wtpJwtSYPNvVxABEB AAG0JkplcmVteSBIYXJyaXMgKG5vbmUpIDxqZ2hAd2l6bWFpbC5vcmc+iQE7BBMBAgAlAhsD BgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAUCVYAYBAIZAQAKCRC85YyM5B8y34iFB/9wozIY RogNdY1aejFFixb6++y4b1riyjMvWEULeEzDlQ0lMT6Z3PxXhZILD4y4aP7Kzx0ozXa5qaKy 41EAPKQoPipnRAH04QytJbIERvz8Tot/LeCVKUc0G9DVxOPBD03czTgqgz4EjV2qvnLF+rTU 0YBevrNCluKosGSd+3RvLWVu0hBhn9pELKfXJNSQXZb+TpHDhSDZ/gCrglBEOhA6YWbDb/4g z+5TFKdk+B++iAQZSHv7zISabjN+BPYgI47A+MU4JycoXaAUnMc0l5ba6fGNaIrzruE4aAZr lP5o+7mlU9Mm0QJqdqYxYPAiplJGrZv+YXH1fp5ueEK3l+NGuQENBFWABsQBCADphLHaKToR uR/E7THerBiCjDatwCaETOKOTY2zRBQpaQ32p/F2XIGLS8Cc27+grZSKQ6ZX0ZN47O+AFyFH F8DH90IXZFpJR3Rb8zgXT8jnLX08DM31eECZHnRzFhGlOmq6WAUlqB3GKCPUCY2c4eTRXyoX LteTxrXCYoj45y/YmvlZrlonBNjPBAyHiO/LNz+V7fZtNsN7N/XGrnLbcdNfNd+SD1ENmbLJ 8RvyymxguTyB/ka9JdjHHIoQEJ6L166B3hhfCHpt8iC0GPZkti9IMl0NoJ029jJm3Jq1qEce EBn5H5QMGn6Fq64iXwTsO1TMNUwpWx8pjvV7wVIxjI8ZABEBAAGJAR8EGAECAAkFAlWABsQC GwwACgkQvOWMjOQfMt9N6Af8CS2CTrMQFdhkGEtBXmL4ifD8UHFkBRBGmM8ZL2fWUBTZXT8m rdRMOK6tcPnKWaCvWvKr0knt970j/DyAgFmH8hgOi3yctigFecVDjjilAeCJMq38s1tYKYiL DbBdHWtdkA9uHZwq3lfd3QxcEEO3QamQF+dO7h8gAOXlG+po87Hm+E0wz4swIB8+S37Jzrx9 uu0LSFDfJCTK+TIKGa5Un8LxPxyq9WnnNDh72zK7BiRidk/s40KcNod83NM4Hn/sbGfyLa8s S0F3ME0S+ocSMOiu/ZHHOiwpLYNbwTJ7stZxGsrguWeT9P+amxbA/YlK95LedstwvN+WcHZ7 d++Arg== Message-ID: Date: Thu, 29 Aug 2019 15:35:55 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit X-Pcms-Received-Sender: [2a00:b900:109e:0:855c:1404:1b9d:3a94] (helo=lap.dom.ain) with esmtpsa Subject: Re: [Ecn-sane] rfc3168 sec 6.1.2 X-BeenThere: ecn-sane@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Discussion of explicit congestion notification's impact on the Internet List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 29 Aug 2019 14:35:58 -0000 On 29/08/2019 14:51, Dave Taht wrote: > On Thu, Aug 29, 2019 at 1:02 AM Jonathan Morton wrote: >> >>> On 29 Aug, 2019, at 5:08 am, Dave Taht wrote: >>> >>> It would explain a lot if this was not actually implemented in Linux. >>> I'm afraid to look. cwnd reduction is capped to 2. 1 should put you >>> in quickack mode AND to go lower seemingly it's supposed to >>> then rely on the retransmit timer. >> >> Nowadays the same effect can be obtained from the pacing timer. Just set the CA scale factor to 50% to get an effective minimum cwnd of 1, or lower still if needed. > > But that wouldn't trigger quickacks from the other side unless it's cwnd 1? I've also seen suggestion of reducing the effective MSS for the duration of really-low-cwnd. Any comments on that? -- Cheers, Jeremy