From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-x52d.google.com (mail-pg1-x52d.google.com [IPv6:2607:f8b0:4864:20::52d]) (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 616863B29E for ; Mon, 23 Sep 2019 07:53:30 -0400 (EDT) Received: by mail-pg1-x52d.google.com with SMTP id c17so7902037pgg.4 for ; Mon, 23 Sep 2019 04:53:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mounce.com.au; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=mciIdyQjaZnqz0+uMDjSIGaJWy83TOsYabZdJTgvly8=; b=Ew67ZEIqDEjx4bPbqkgK0QyB5td7gvkKYOkTmuf588VnsVkPYGNvAJ+e+lTUNXgrMi iTV4GdaPO3OOAlBb3P4JShxx2RxwWSTtqMNhwkDV2sjfnhrLSOxLsfqNdu5iYN6rZjaF /NOkrqOMj8+WvL6K9KcMPvzir7xPazk7gJ1NWVXSj4Za6JFFuV8LcieGsQum1omI/Ii6 iXr4X+u9RoSC9F/4DL5lYnAdR25vyVQW7wngLSdwvKYINkXLqKNIqL/U9q3FsZ2nEExi a2uaYBR5tb0pP/8kzDImEr31uW8botNb6MWK5bmB3CBm7Ym0ffhHos8rLQ7eoyt+kjjG bQxA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=mciIdyQjaZnqz0+uMDjSIGaJWy83TOsYabZdJTgvly8=; b=nU7PRvhm5XyAGEIhQcgHwFQWz9e6gH5koOSpNoA3GF1Ce0vltJ0x7stsRXWAZi0EBQ TPIK/WNk7PvL1VBRnpasbCGZT2XI4IxU34gywIqDMj4se1XxgfVDKs/T+KD9z/Brbc6F D3ILRTKqOqCw/8Wr9JspztgpI5vFTSS0NhFrdc4OD43TNe1Hdg8zHnWbmAY4oCEEJBo3 V2JnCMTt5xVfNt0Ld24tkTdSmi4RE2W9iXmEW4/KEXv6QLef2W/y8/v27snvw5MfBAig BtdDng95Mn62L2Lx4QiMkjbl5aUHgS87s/6G8NN0YjX+kyVG3Xea1u2XuJTjOSDyJTk3 SdDQ== X-Gm-Message-State: APjAAAUl7KZ1vfsWevD5wlTGopbIWWDtxu/wY9voJFXL2NawMRfCxMMr zFIwagfNUHpkm8475IB2Kze7D+UQNucLadBfVReWQA== X-Google-Smtp-Source: APXvYqw7ObNGfPA7rqH4FdhgW2wv7gHQIu8TaP2ElMFvjHQBy80V2/mXZnTcU3axEzk5rnpDCLo7U8cY/2ejNkaAnbc= X-Received: by 2002:a65:6798:: with SMTP id e24mr17322541pgr.39.1569239609426; Mon, 23 Sep 2019 04:53:29 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Ryan Mounce Date: Mon, 23 Sep 2019 21:23:18 +0930 Message-ID: To: Jonathan Morton Cc: marco@heavenlysanctuary.com, Cake List Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [Cake] Frontier FIOS Framing X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 23 Sep 2019 11:53:30 -0000 On Mon, 23 Sep 2019 at 13:56, Jonathan Morton wrote= : > > The overhead compensation matters more with small packets than with the l= arger ones used for bulk transfers; for the latter, reserving a little more= bandwidth will appear to make everything work. For fibre I would try "eth= ernet" and reserve about 1% bandwidth each way, then if possible test to se= e whether there is any bloat. The "ethernet" keyword is perfect for shaping real line rate ethernet, however it's more likely that the upstream ONU/OLT/BNG is shaping/policing without regard for the 8 byte preamble + 12 byte inter-frame gap. It's almost certainly blind to the native GEM framing of GPON. My starting point would be "mpu 64 overhead 18". There are possibly VLAN tags in use behind the scenes, so try incrementing overhead by 4 from there. For example, this is the simplified cake incantation for the upstream of my 100/40 GPON connection: tc qdisc replace dev eth2 root cake dual-srchost nat mpu 64 overhead 26 bandwidth 40Mbit There are 2 VLAN tags added by the OLT before my upstream traffic is policed by an aggregation switch, so 18 bytes ethernet (incl. FCS) + 4 bytes VLAN + 4 bytes VLAN =3D 26 Correspondingly in the downstream I use: tc qdisc replace dev ifb2 root cake ingress dual-dsthost nat mpu 64 overhead 26 bandwidth 99Mbit As alluded to by Jonathan, the 1% margin is required in order for cake to reliably enforce host/flow fairness on downstream/"ingress" traffic. So long as mpu/overhead/bandwidth are fine tuned, I haven't needed to allow for any margin in the upstream. -Ryan