From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qa0-x230.google.com (mail-qa0-x230.google.com [IPv6:2607:f8b0:400d:c00::230]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id E37F421F19C for ; Sat, 11 Jan 2014 11:06:41 -0800 (PST) Received: by mail-qa0-f48.google.com with SMTP id f11so937323qae.7 for ; Sat, 11 Jan 2014 11:06:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=content-type:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=ed3ZgWAYBp2fQCDs5ii/fHIFOwteXIFEC9abGXd03Xw=; b=pUbmsEk3LCQAT4cncs3Sb4qjoy9TW90etMVJ4TrfI0mzmgT2uHZTL8w+f8lpKTYihM YiYAe9ikP/3jZly5zSBmKS/XrgOVl0s8VPvimDwxmedBHCp1JhXmosjFjWuAIHCKxjf4 tLNXbHacZpyh/hZG6N1q9K/MalvNzMU5bC8vg/W3YocDoOtWpyZJxZjEsnnMu8QlBzUl DXgBJwZXUD+Xj2A/DSjWzEsBb+ICPRCbCFA6j9p7HHcDF0J3wP4mAttOTKKts+muIIPA l0a+hNlzRChO3cU+gNLcpzFCjNbIlbOjJoulcUrZlu2FO3E9mgFzeO/b6sKqemFDL5/d nWPA== X-Received: by 10.49.25.137 with SMTP id c9mr6227240qeg.12.1389467200892; Sat, 11 Jan 2014 11:06:40 -0800 (PST) Received: from richs-mbp-2018.home.lan ([64.223.225.159]) by mx.google.com with ESMTPSA id x8sm12732567qed.9.2014.01.11.11.06.39 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sat, 11 Jan 2014 11:06:40 -0800 (PST) Content-Type: text/plain; charset=windows-1252 Mime-Version: 1.0 (Mac OS X Mail 7.1 \(1827\)) From: Rich Brown In-Reply-To: Date: Sat, 11 Jan 2014 14:06:38 -0500 Content-Transfer-Encoding: quoted-printable Message-Id: <10B5A5C1-A4D7-429D-A57D-21612B5169E1@gmail.com> References: <4B0976EC-5224-4E81-B5DF-96A85424FB6E@gmail.com> <49DBDBE7-BF76-4823-B723-670935A55833@gmx.de> To: Sebastian Moeller X-Mailer: Apple Mail (2.1827) Cc: cerowrt-devel Subject: Re: [Cerowrt-devel] VDSL X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Development issues regarding the cerowrt test router project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 11 Jan 2014 19:06:48 -0000 Hi Sebastian, >>> Well, that looks like a decent recommendation for the wiki. The = SQM configuration page still needs to expose all three values, atm, = ethernet, and none so that people can actually change things... >>=20 >> So two questions really: >>=20 >> 1) (=46rom my previous note) What=92s the difference between the = current =93Ethernet=94 (for VDSL) and =93None=94 link layer adaptations? >=20 > Currently, "none" completely disables the link layer = adjustments, "ethernet" enables them, but will only use the overhead = (unless you specify an tcMPU, but that is truly exotic). >=20 >>=20 >> 2) When we distinguish the Ethernet/VDSL case, I would really like to = use a different name from =93Ethernet=94 because it seems confusingly = similar to having a real Ethernet path/link (e.g., direct connection to = internet backbone without any ADSL, cable modem, etc.)=20 >=20 > On the one hand I agree, but the two options are called "ATM" = (well for tc "adsl" is a valid alias for ATM) and "ethernet" if you pass = them to tc (what we do), and I would really hate it to hide this under = fancy names. I see no chance of renaming those options in tc, so we are = sort of stuck with them and adding another layer of indirection seems = too opaque to me. This is why I put some explanation behind the option = names in the list box=85 Now I see how it works. (I didn=92t understand that =93None=94 really = meant NONE.) The following choices in the Link Layer Adaptation would = have eased my confusion: - ATM (almost every type of ADSL or DSL) - Ethernet with overhead - None (default) Then the text can say: =97 You must set the Link Layer Adaptation options so that CeroWrt can = perform its best with video and audio chat, gaming, and other protocols = that rely on short packets. The general rule for selecting the Link = Layer Adaption is:=20 * If you use any kind of DSL/ADSL connection to the Internet (that is, = if you get your internet service through the telephone line), you should = choose the =93ATM (almost every type of ADSL or DSL)" item. Set the = Per-packet Overhead to 44.=20 * If you know you have a VDSL connection, you should choose =93Ethernet = with overhead" and set the Per-packet Overhead to 8.=20 * If you use Cable modem, Fiber, or another kind of connection to the = Internet, you should choose =93None (default)=94. All other parameters = will be ignored. If you cannot tell what kind of link you have, first try using "None", = then run the [[Quick Test for Bufferbloat]]. If the results are good, = you=92re done. Next, try the ADSL/ATM choice, then the VDSL choice to = see which performs best. Read the **Details** (below) to learn more = about tuning the parameters for your link.=20 =97 Would that be better? Thanks. Rich=