From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 9AFB33B2A4 for ; Tue, 16 Jun 2020 08:03:49 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1592309029; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=gE0Ras7RAmMS8kc2jI1XGP69FTOPIDvXQGZJyZl2At8=; b=hC5UKkVyo56nQQ3MfpQvr2x0g7BCl0q+/EcgQC1pEl5vanEmpDv5CVO6aRy/eoSPVdhtt2 GOZkKCaXIHOyNJZ8aKogewsK9OXhj9xhRLJwWSTfOSODIVFA27aUjKqMl6Zp7SCa1RqwUK 9v2VWjvUzLRoNjqYIZ/7XeQs6B3eI2I= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-198-u6hdyhgGNvCS-YANtwfx6A-1; Tue, 16 Jun 2020 08:03:47 -0400 X-MC-Unique: u6hdyhgGNvCS-YANtwfx6A-1 Received: by mail-wm1-f71.google.com with SMTP id j128so1150418wmj.6 for ; Tue, 16 Jun 2020 05:03:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version:content-transfer-encoding; bh=o/otPPQTcnYJashadYK5mjf/0c8+yHZgkhWyMLAES/g=; b=m1xUZ9todqUqvit/7hCK8Ka74fM4w2QLPbaOaAjlhcaSh8I6KpuHIamUkxQ36Hem9i d3Srd6WPyM/tzbPubbc7fFFW5Df9kXlfvUcfaj3b6Wj5SkHHsm0p3Ro//iyHXK6PXMvy WwQQSJxx9Fu5HPokRBCit8oOsCPsBADXoijiRPyomVbOgP+i6ghb+qQb/Eml7hEOaXM5 Q9ic0BK6sMU5SZ9FHO2Dpyj1JwKPktfLEv9DG02r9hvzPdP/WfLWswNDREdjZ1j71wta U6+NCzVY3NuIrPqgdL9NUdbJN77VpX1Nove8J+PJFX+JSwCkE6PZdwLlHBsdZAzFgTYs 2MJA== X-Gm-Message-State: AOAM530kdID2b3FdYYGfQgZvJyZAluUXhR4wV7UVirzQppTIXHIu40J4 n8mkELt5NVE7uvDEjQrb1h5oJF10qtkbntMxi7hbwIYZlsnRxyOoPe5ZJTmY+53uwzLbT7XD663 glBrb3Ev1r+kH+T5Esi4LWQgJXWa9VAosCfg= X-Received: by 2002:a5d:49c5:: with SMTP id t5mr2808882wrs.18.1592309026320; Tue, 16 Jun 2020 05:03:46 -0700 (PDT) X-Google-Smtp-Source: ABdhPJz5yPYW1UJz5iqgKi0d/lSLOCiDUwPd1dZv9NUuVJdNajwThKL4wV+BZFAAq2veGzlVkZwLUQ== X-Received: by 2002:a5d:49c5:: with SMTP id t5mr2808849wrs.18.1592309025961; Tue, 16 Jun 2020 05:03:45 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([45.145.92.2]) by smtp.gmail.com with ESMTPSA id s8sm30159106wrg.50.2020.06.16.05.03.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Jun 2020 05:03:45 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id EF4EA181514; Tue, 16 Jun 2020 14:03:43 +0200 (CEST) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Sebastian Moeller Cc: Michael Yartys , Michael Yartys via Make-wifi-fast In-Reply-To: <709555FC-4203-486B-8B40-86FAD9F0294C@gmx.de> References: <87sgevz1iu.fsf@toke.dk> <709555FC-4203-486B-8B40-86FAD9F0294C@gmx.de> X-Clacks-Overhead: GNU Terry Pratchett Date: Tue, 16 Jun 2020 14:03:43 +0200 Message-ID: <87lfknz080.fsf@toke.dk> MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Make-wifi-fast] Higher latency on upload under poor signal conditions 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: Tue, 16 Jun 2020 12:03:49 -0000 Sebastian Moeller writes: > Hi Toke, > > >> On Jun 16, 2020, at 13:35, Toke H=C3=B8iland-J=C3=B8rgensen wrote: >>=20 >> Sebastian Moeller writes: >>=20 >>> Hi Michael, >>>=20 >>>=20 >>>> On Jun 16, 2020, at 12:18, Michael Yartys via Make-wifi-fast wrote: >>>>=20 >>>>=20 >>>> From: Michael Yartys >>>> Subject: Higher latency on upload under poor signal conditions >>>> Date: June 16, 2020 at 12:18:38 GMT+2 >>>> To: "make-wifi-fast@lists.bufferbloat.net" >>>> Reply-To: Michael Yartys >>>>=20 >>>>=20 >>>> Hi >>>>=20 >>>> I decided to run some 8-stream TCP tests at the edge of the range of m= y WiFi network, and I noticed that I get higher latency when I run an uploa= d compared to a download. The latency when downloading is pretty steady at = right above 30 ms, and when I run the upload it hovers around 80-100 ms. I = think I know why this happens, but I would like to read the opinion of the = mailing list. >>>=20 >>> =09My naive guess would be that air-time fairness by the AP only direct= ly affects the AP's own transmissions, the stations will in all likelihood = not have an fq_codel instance in its wifi-stack (I could be wrong, but I do= not believe that the 7260ac intel card actually uses airtime fairness yet/= at all). So the 80-100ms might just come from the default wifi parameters w= hich typically are adjusted for peak thoughput instead of a balanced throug= hput latency under load set-point. Then again that is my _guess_, so Kruger= -Dunning might apply. >>=20 >> 'iw' will tell you: >>=20 >> $ iw phy | grep TXQ >> =09=09* [ TXQS ]: FQ-CoDel-enabled intermediate TXQs > > =09Sweet! Thanks, as I hedged above, it seems like I am/was in Kruger-Dun= ning territory ;) > >>=20 >> $ lspci | grep Wireless >> 02:00.0 Network controller: Intel Corporation Wireless 8265 / 8275 (rev = 78) >>=20 >> Other than that, the 'lots of retries' theory does sound plausible. Or >> it could be buffering in the firmware. Or a combination of all of that := ) > > =09Out of curiosity, how would one see the retries? Some hardware has counters, but not sure if the Intel devices expose anything. Otherwise, you'll need to sniff the air I'm afraid :/ -Toke