From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-x230.google.com (mail-wr0-x230.google.com [IPv6:2a00:1450:400c:c0c::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 4AAFC3CB3A for ; Sat, 13 Jan 2018 05:53:11 -0500 (EST) Received: by mail-wr0-x230.google.com with SMTP id f8so7425890wre.4 for ; Sat, 13 Jan 2018 02:53:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=fLYmXUsh5l7QmmoV0zZMRx7X++YuJwQZPlmp3m2Tgj0=; b=NNZjWw2yaXz9kqcGAfMx9FBRWPQ7RC0bzSRHIr9VRZtHaDUHO6vzCsuLrMqiMQ4WKw TmUOqG0t8DAaToSWLpoRaCtdJVcMPColJ3UNmdSK/PUwc5cX771xSNe/mbO/0uKk+Nz1 AzgK+f9EWwGz/qu4jRjXwEWaNVDQXsWVc0qT3ayW6WDr5PojcPDWK+Kdsec784vYoDZA 9OJWTf/Uuj5HfTni/wvcAU6vlOg/qF7HCizLUiOXJzPfCp74zgbaT8rKUW9sznO0ycLH qPj0hQ+SWFAjPzpij87n/MtQ4K8ri1KeNzGc2zrY5E9aLas95UoAKYXlMDyRquBZcX4Z StiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=fLYmXUsh5l7QmmoV0zZMRx7X++YuJwQZPlmp3m2Tgj0=; b=iyVepgpWi/vc4ptdKNXQqTUrj76UOM2n84ROfxfkmj9vqRvkACd/WTbeqKGkm4gOPE nz/50IvTKW8KwJlGEP9UG/dQ2kn08FxuqeLyDlB2h65WL3SsUjpiMHhI3kfcS52Ys/Zl T3J6OIO70tuMxx56Jm4o/OZavzZtdXi1jmmd0UcyNEv5UCYzG933clIzrEJTC0VChz4I e/HEcxDhrKFyyqF+5B92GxRICr14Pg7cL1x8AxX3+pZ6hkI7FguXCMyvGETITOmbJj5H i0ydDpcPyuyMCTDDYXfkVnUUeD0m08N6jZ2dXljZCUZgJg019DFZlY31VHZCi/jF8q5g j0mw== X-Gm-Message-State: AKwxytest3vMGEKMArOnufr6XgZ69/zqZdUUKJWp7L2l61zeSGUmWSV/ wYgHTYygdjxbSFmtK9Ul8KYnQaCh X-Google-Smtp-Source: ACJfBov3mxLZ82jTm4k4ypPIPnl7VNemCXp2QEdZXHzkSpTp5Dfn9WIWrxpI4Tb83GHk93ez2Nt85A== X-Received: by 10.223.164.206 with SMTP id h14mr14213446wrb.229.1515840790338; Sat, 13 Jan 2018 02:53:10 -0800 (PST) Received: from [10.72.0.20] (h-1169.lbcfree.net. [185.193.85.130]) by smtp.gmail.com with ESMTPSA id c19sm3243959wmd.5.2018.01.13.02.53.08 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Sat, 13 Jan 2018 02:53:09 -0800 (PST) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) From: Pete Heist In-Reply-To: <87o9lzqmsq.fsf@toke.dk> Date: Sat, 13 Jan 2018 11:53:09 +0100 Cc: make-wifi-fast@lists.bufferbloat.net Content-Transfer-Encoding: quoted-printable Message-Id: <1265AA25-398F-4FA1-9D6B-279178D52EEB@gmail.com> References: <87o9lzqmsq.fsf@toke.dk> To: =?utf-8?Q?Toke_H=C3=B8iland-J=C3=B8rgensen?= X-Mailer: Apple Mail (2.3124) Subject: Re: [Make-wifi-fast] Estimating WiFi congestion using different-prio pings X-BeenThere: make-wifi-fast@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 13 Jan 2018 10:53:11 -0000 > On Jan 12, 2018, at 1:33 PM, Toke H=C3=B8iland-J=C3=B8rgensen = wrote: >=20 > Some people over at Skype have implemented a technique for a client to > estimate congestion at the WiFi AP by pinging the AP at VO and BE > priority and measuring the difference in response times. Pretty neat, > except that it would presumably break if the AP was = FQ-CoDel-enabled... >=20 > Paper here, including a description of the bandwidth estimation stuff > they apply to Skype based on the information: > https://dl.acm.org/citation.cfm?doid=3D3143361.3143390 >=20 > -Toke Interesting, I wonder if this could be used to evaluate congestion = within an ISP=E2=80=99s backhaul (but the article is behind a paywall). FreeNet Liberec currently uses SmokePing with ICMP. They have dozens of = APs, but here=E2=80=99s what results look like to the AP I use: = http://www.drhleny.cz/bufferbloat/smokeping/vysina.png They=E2=80=99re not all as rosy: = http://www.drhleny.cz/bufferbloat/smokeping/studankaA.png When I get back to it, I want to write a SmokePing plugin for irtt to = try in the same environment. The results may be interesting, because = I=E2=80=99ve proven for myself that Ubiquiti is prioritizing ICMP, so I = suspect that what we=E2=80=99re seeing in the SmokePing results is a = measure of connectivity and maybe contention as well, but not congestion = or user-perceived latency. And even though the ping results to my AP = don=E2=80=99t vary much, I feel like web surfing latency varies = considerably, maybe dramatically, depending on the time of day. I=E2=80=99= d like to prove that. The summary of what they did at Skype makes me think it would also be = interesting to see the _difference_ between ICMP and irtt (UDP at best = effort)... Pete