From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-x232.google.com (mail-wr0-x232.google.com [IPv6:2a00:1450:400c:c0c::232]) (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 C82323B29E for ; Tue, 24 Apr 2018 09:37:42 -0400 (EDT) Received: by mail-wr0-x232.google.com with SMTP id v60-v6so49979885wrc.7 for ; Tue, 24 Apr 2018 06:37:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=eventide.io; s=google; h=mime-version:subject:from:in-reply-to:date:cc:message-id:references :to; bh=s+LyIsLsGnlBu3tmt1C11Dpg4Bv4Ius52zixJJBJ9oc=; b=KXkx+TvmzvGTIIm89mjbJ0f3e9QqPArg+lQb62d1WKKNFGJebSSgQZuWdTLAX6dyB3 4p5EUc2wdoO0pVGCjx/POBHqsmRZdWLY2lngcRnEQN345xWeH6PWnpS/3kmLM6vhpPko mK84LtZ21S+/y5I0OaE7A9mobAhuaEccAPuMJPZL2hPQqA7jBxo7nIpHZhxYl+RJv6v4 mFyWPS3vZ9+Uu/ybHyYv/F5ZiQJe3yI0hxiwzKu3VAbgjMfFr6TZ2k2VGx6Iae9fnVH+ LwDpAcf5A8B73TC8w/bQvdUalntMftTwrv1mL6RjcoZykBgW26+ZEC4Ae4p7N8ZBhTvU z05Q== 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 :message-id:references:to; bh=s+LyIsLsGnlBu3tmt1C11Dpg4Bv4Ius52zixJJBJ9oc=; b=LkckDmSIQyFrxzrvpWw9qbeO1/Rybk9KnU9JCrmLA691dPNP/lLQNPc6NWmsRhvFFL 4nrbM1atJ7lgdIWvKNyESWEcfKjB/oT8DuLEo9cf/Et33yY008fvJ39+3ARQ62ubG3b1 qkP2M9zM0aLcJDKQsgNpJXLiijq2OdRUrEFk5oeUY231GnFGk2n3pWNc7sJ7nxEKKspd /C4VmevEWra+Y5Wyh3kB97Mge2nuNbFsXJm3JuZi3XlDvNNzn9B6Ez31ueZZrqRjpuqs lySBFfzCS5N2pXwSBwiZv9cTFqdMD3PLT+86uKhw/lasWKcDBYKffPn5EwnW0EF2n6Vm SIAQ== X-Gm-Message-State: ALQs6tD9DhQ454LhPHB5EGlfLY10FTT0LmJJSfjzZGIytixc/VyZNi3I Y8lOAquRDPWKS51ABUDiPU6+Effmtns= X-Google-Smtp-Source: AIpwx4/QC15BHMS0I3oqM7KTotItFvI8wBuekopO5NAsP4Y29Rs9jamhtex9rsXhGuBnlqy6qW5p9Q== X-Received: by 2002:adf:afce:: with SMTP id y14-v6mr21191873wrd.249.1524577061865; Tue, 24 Apr 2018 06:37:41 -0700 (PDT) Received: from tron.luk.eventide.io (h-1169.lbcfree.net. [185.193.85.130]) by smtp.gmail.com with ESMTPSA id i30-v6sm28085290wra.38.2018.04.24.06.37.40 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 24 Apr 2018 06:37:41 -0700 (PDT) Content-Type: multipart/alternative; boundary="Apple-Mail=_5CBD9014-09E7-4103-A852-BCB560BB7F34" Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) From: Pete Heist In-Reply-To: <871sf495vs.fsf@toke.dk> Date: Tue, 24 Apr 2018 15:37:40 +0200 Cc: make-wifi-fast@lists.bufferbloat.net Message-Id: References: <66BDCA6E-D7C4-4E76-8591-8FDC35B09EA3@eventide.io> <871sf495vs.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] mesh deployment with ath9k driver changes 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, 24 Apr 2018 13:37:43 -0000 --Apple-Mail=_5CBD9014-09E7-4103-A852-BCB560BB7F34 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 > On Apr 24, 2018, at 1:54 PM, Toke H=C3=B8iland-J=C3=B8rgensen = wrote: >=20 > Pete Heist > writes: >=20 >> Mean ping time for >> cabin 12 is around 200 ms during =E2=80=9Cactive use=E2=80=9D, with = outliers above 1 >> second, which is higher than expected. I don=E2=80=99t have data = collected on >> how many active users that is and what they=E2=80=99re doing, but = there could >> be 40-50 students around the cabin 12 AP, with however many active = "as >> is typical for kids=E2=80=9D. >=20 > Hmm, yeah, 200ms seems quite high. Are there excessive collisions and > retransmissions? Hrm, how would I know that actually? /proc/net/wireless has all zeroes = in it. I don=E2=80=99t see it anywhere in output from =E2=80=98iw=E2=80=99= ... > Is the uplink on the same frequency as the clients? Most definitely, the OM2P-HS is a single channel (2.4 GHz) device, with = dual antennas. I was hoping the new driver could make the best of this = situation. :) Now, my ping test goes from the gateway straight to the repeater, so = there=E2=80=99s only one WiFi hop in my ping results. I don=E2=80=99t = know how pings actually look for clients while the AP is under load. I = suppose I=E2=80=99ll either have to test that manually when I=E2=80=99m = on site, or set up a fixed wireless SmokePing instance to simulate a = client. I wish I could cable everything, but it isn=E2=80=99t physically = practical. The next possibility is dual channel APs, or separate = backhaul links, all costing something... Cabins 12 and 20 hang off the same gateway (which are all on the same = channel, obviously). That will mean more collisions between them. Cabin = 28 is the only repeater on its gateway, so is likely to be better. = It=E2=80=99s an interesting setup from the standpoint that it=E2=80=99s = not very large, but tests a few different single channel repeater = scenarios. >> Overall it would be nice to know, in a typical real-world setup, how >> much is WiFi latency is due to bufferbloat, and how much to the >> physical layer? >=20 > On ath9k bufferbloat should be more than 10-20ms or so. My pings can definitely be in the ether for longer than that, for some = reason=E2=80=A6 :) --Apple-Mail=_5CBD9014-09E7-4103-A852-BCB560BB7F34 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8
On Apr 24, 2018, at 1:54 PM, Toke H=C3=B8iland-J=C3=B8rgensen = <toke@toke.dk> = wrote:

Pete Heist <pete@eventide.io> writes:

Mean ping time for
cabin 12 is around 200 = ms during =E2=80=9Cactive use=E2=80=9D, with outliers above 1
second, which is higher than expected. I don=E2=80=99t have = data collected on
how many active users that is and what = they=E2=80=99re doing, but there could
be 40-50 students = around the cabin 12 AP, with however many active "as
is = typical for kids=E2=80=9D.

Hmm, yeah, 200ms = seems quite high. Are there excessive collisions and
retransmissions?

Hrm, how = would I know that actually? /proc/net/wireless has all zeroes in it. I = don=E2=80=99t see it anywhere in output from =E2=80=98iw=E2=80=99...
=

Is the uplink on the = same frequency as the clients?

Most definitely, the OM2P-HS is a single channel = (2.4 GHz) device, with dual antennas. I was hoping the new driver could = make the best of this situation. :)

Now, my ping test goes from the gateway straight = to the repeater, so there=E2=80=99s only one WiFi hop in my ping = results. I don=E2=80=99t know how pings actually look for clients while = the AP is under load. I suppose I=E2=80=99ll either have to test that = manually when I=E2=80=99m on site, or set up a fixed wireless SmokePing = instance to simulate a client.

I = wish I could cable everything, but it isn=E2=80=99t physically = practical. The next possibility is dual channel APs, or separate = backhaul links, all costing something...

Cabins 12 and 20 hang off the same gateway (which = are all on the same channel, obviously). That will mean more collisions = between them. Cabin 28 is the only repeater on its gateway, so is likely = to be better. It=E2=80=99s an interesting setup from the standpoint that = it=E2=80=99s not very large, but tests a few different single channel = repeater scenarios.

Overall it would be nice to know, in a typical = real-world setup, how
much is WiFi latency is due to = bufferbloat, and how much to the
physical layer?

On ath9k bufferbloat should be more than 10-20ms = or so.

My pings = can definitely be in the ether for longer than that, for some reason=E2=80= =A6 :)

= --Apple-Mail=_5CBD9014-09E7-4103-A852-BCB560BB7F34--