From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-x236.google.com (mail-wm0-x236.google.com [IPv6:2a00:1450:400c:c09::236]) (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 7015E3BA8E for ; Mon, 9 Jul 2018 02:27:43 -0400 (EDT) Received: by mail-wm0-x236.google.com with SMTP id v25-v6so19911784wmc.0 for ; Sun, 08 Jul 2018 23:27:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=heistp.net; s=google; h=from:message-id:mime-version:subject:date:in-reply-to:cc:to :references; bh=9gg9GhEAd1Z4vazrV9LWrtJi9pknleBpP+5OMtR/TSo=; b=jmU17GoDVibWRhHEMo1qKHkZubTqL/g4IwBaE/eipgd/2iqFaF5u1UEIEwYekXyJp6 AKG2Qarfg1WUOaSZhPOBTZj4dHSxIoQ0vSS0uMo0wQT1YXai6LhB3y7y26uLT6IYxd7j 5o9kHoUrrrXklB6S0DsBkLXWaV2klvTTyt6MyzOLNXhdcYKWeNypeKAQ3C3PuRU0G1HX 2TQhyIbYukhcXx9rXLMEeQzdIjkoG97ElpwpfkDnCB4J6PkFwEOdY/PqFJfi8ZkCdKho SEnDl/6gGO12kdoOQ4+4MaQNCqHIwLVzn74aontQLs7DYQMuJGvfsipb4zPtZls1mcQO gnVg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:message-id:mime-version:subject:date :in-reply-to:cc:to:references; bh=9gg9GhEAd1Z4vazrV9LWrtJi9pknleBpP+5OMtR/TSo=; b=Z6rkdeBdOBr+Fw8/oc4A+dWp2H1asrqc+1F1x41F44sHd2rJYba5e2Ob7xC0y6QbUi irTR0fAT5+Z58Mz+nqFne6acsNToqVTMaZ1vensg/mkFrndGBb1Pu290wh/VhJiQJf29 oZyeSYwOjX3ZyLIq3+aVKbwTZbte0gPpOdTdikJlqmitp7m7dhhSPnGDruQaYwtQdm4q DmkzX6v7jZ8VVhXTZlYHuNO4KAcLjsFXdR2yPvmwsRbRkGoi/+YayQDwll1aA9blh3KO /VE0jC6RnJ1CRx86hPQ/b5oWYy4ATsbxxE3FaqPkQr0MEMCfLhS+GnjI5MfxEq1rQ8Pg IP1g== X-Gm-Message-State: APt69E3oJC6t5eDGxlI+Vi7vRgfnu0LeV5sNiDkfJWR6c2B7H227YXYl BOu4amlR76OYcKE2r0xdoZxShh6rP+I= X-Google-Smtp-Source: AAOMgpc+1ANhtXePAU+JIbini2vIkdtMUFXgUySfR8RTz8cx5jjgZChFy/1Wf7LgkK9rfYaesUI+Dw== X-Received: by 2002:a1c:5f82:: with SMTP id t124-v6mr11304386wmb.14.1531117662518; Sun, 08 Jul 2018 23:27:42 -0700 (PDT) Received: from tron.luk.heistp.net (h-1169.lbcfree.net. [185.193.85.130]) by smtp.gmail.com with ESMTPSA id n8-v6sm14381793wrt.56.2018.07.08.23.27.41 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 08 Jul 2018 23:27:41 -0700 (PDT) From: Pete Heist Message-Id: Content-Type: multipart/alternative; boundary="Apple-Mail=_58880C2C-30E8-4595-A68B-6CCB73F63863" Mime-Version: 1.0 (Mac OS X Mail 11.4 \(3445.8.2\)) Date: Mon, 9 Jul 2018 08:27:40 +0200 In-Reply-To: Cc: Aaron Wood , Make-Wifi-fast To: Jonathan Morton References: <9E7E043B-2373-46ED-B122-38A287422999@eventide.io> <87d0wu7rbg.fsf@toke.dk> <8A44F1D4-1EB8-4D46-85F9-00C7307FF2D4@heistp.net> <2EC1279B-76C6-48C0-AED4-E9C4A7D0F004@heistp.net> <874lhdeso1.fsf@toke.dk> <87fu0xd1o9.fsf@toke.dk> <663D9F58-3202-42CD-9BD5-3B415E77EE97@heistp.net> X-Mailer: Apple Mail (2.3445.8.2) 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: Mon, 09 Jul 2018 06:27:43 -0000 --Apple-Mail=_58880C2C-30E8-4595-A68B-6CCB73F63863 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 > On Jul 9, 2018, at 7:17 AM, Jonathan Morton = wrote: >=20 >> On 9 Jul, 2018, at 5:20 am, Aaron Wood wrote: >>=20 >> Do the AP-to-AP links use the same packet scheduling as the AP-to-STA = links? (especially the prohibition on aggregation for VO, which seems = counter-productive on a backhaul link). >=20 > I believe they do, since they go through the same type of MAC grant = process. To avoid that, the AP would need to ignore the traffic class = when assigning backhaul packets to queues. I=E2=80=99m also almost sure of that. However, since I set all DSCP = values to 0 in PREROUTING, most traffic going over the backhauls is now = best effort, and I haven=E2=80=99t been able to detect a change in ping = times to the APs. The change was made July 5 around 10am and, for = example, this is probably our most challenged AP: = https://www.drhleny.cz/smokeping/Cabin12.html = I still think making backhaul traffic best effort makes sense. In my = point-to-point tests, I sometimes do this using IPIP tunnels, so the = DSCP value of the inner packet is hidden from the WiFi stack, but the = value is still maintained after it passes through the tunnel. A drawback = of this is that the MTU is shortened by 20 bytes. Tomorrow I=E2=80=99ll be setting up a 5GHz point-to-point backhaul link = for Cabin 28 (higher standard cabins), so I expect a significant change = there.= --Apple-Mail=_58880C2C-30E8-4595-A68B-6CCB73F63863 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8
On = Jul 9, 2018, at 7:17 AM, Jonathan Morton <chromatix99@gmail.com> wrote:

On 9 Jul, 2018, at 5:20 = am, Aaron Wood <woody77@gmail.com> wrote:

Do the AP-to-AP links use the same packet scheduling as the = AP-to-STA links? (especially the prohibition on aggregation for VO, = which seems counter-productive on a backhaul link).

I believe they do, since they go = through the same type of MAC grant process.  To avoid that, the AP = would need to ignore the traffic class when assigning backhaul packets = to queues.

I=E2=80=99m also almost sure of that. = However, since I set all DSCP values to 0 in PREROUTING, most traffic = going over the backhauls is now best effort, and I haven=E2=80=99t been = able to detect a change in ping times to the APs. The change was made = July 5 around 10am and, for example, this is probably our most = challenged AP: https://www.drhleny.cz/smokeping/Cabin12.html

I still think making = backhaul traffic best effort makes sense. In my point-to-point tests, I = sometimes do this using IPIP tunnels, so the DSCP value of the inner = packet is hidden from the WiFi stack, but the value is still maintained = after it passes through the tunnel. A drawback of this is that the MTU = is shortened by 20 bytes.

Tomorrow I=E2=80=99ll be setting up a 5GHz point-to-point = backhaul link for Cabin 28 (higher standard cabins), so I expect a = significant change there.
= --Apple-Mail=_58880C2C-30E8-4595-A68B-6CCB73F63863--