From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.15.18]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (Client CN "mout.gmx.net", Issuer "TeleSec ServerPass DE-1" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id EF52421F1F1 for ; Wed, 18 Dec 2013 14:43:18 -0800 (PST) Received: from hms-beagle-3.home.lan ([217.86.119.32]) by mail.gmx.com (mrgmx103) with ESMTPSA (Nemesis) id 0LfTC1-1V9cdf2YkT-00p19u for ; Wed, 18 Dec 2013 23:43:14 +0100 Content-Type: text/plain; charset=windows-1252 Mime-Version: 1.0 (Mac OS X Mail 6.6 \(1510\)) From: Sebastian Moeller In-Reply-To: <0E267F91-3CC8-48F4-92C0-AD8BACA98FCC@gmail.com> Date: Wed, 18 Dec 2013 23:43:13 +0100 Content-Transfer-Encoding: quoted-printable Message-Id: <1FA2FD44-D715-4B50-BB5A-BAF61070970B@gmx.de> References: <34E77F64-739C-49E4-B8A4-6ABBEAE4174B@gmail.com> <8DB84101-C942-49C4-99F0-6C9319961297@gmail.com> <22176178-A50F-48F2-A3A1-D3853764AD0E@gmail.com> <0E267F91-3CC8-48F4-92C0-AD8BACA98FCC@gmail.com> To: Rich Brown X-Mailer: Apple Mail (2.1510) X-Provags-ID: V03:K0:Hve36KDrsc3ty9onP1pWZBdQnvMo2Avi5rOCptsiwR6nIMXqgS2 lg/z9Tdt1urQat36ymDGtfZL7iwqSNTyDlxnuqTtWJeIoOwa+ouPVkZc8OhUyS5oLeNpelJ SbKVU+U0m34d1Bc8UV57/ZlZbg9IPXjDEYZGhdBBlT5Dcanusv3kRydm4El1D9Lh9vvXYIp u844abi2tmRr4w4AE+H1Q== Cc: cerowrt-devel@lists.bufferbloat.net Subject: Re: [Cerowrt-devel] cerowrt-3.10.24-5 dev build released 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: Wed, 18 Dec 2013 22:43:19 -0000 Hi Rich, On Dec 18, 2013, at 14:58 , Rich Brown wrote: > I like David Lang=92s questions: >=20 > 1) If we had =93full knowledge=94 of the customer=92s link, how many = different cases would we have to take into account? >=20 > 2) What happens if we get it wrong? >=20 > And I think I understand Sebastian Moeller=92s answers: >=20 > 1) People using ATM-based carriers need the ATM link layer adaptation = calculation; others (PTM, Cable, Fiber, etc.) don=92t need that = calculation. Except even with PTM or Fiber there still might be the need to = specify an overhead (e.g. 8 bytes for PPPoE) in this case one needs to = select the "ethernet" link layer... >=20 > 2) Getting it wrong hurts in each case, but it seems worse where = people are using PTM or Ethernet-based links since they lose 10% of = their bandwidth due to the 48 in 53 bytes encapsulation. Failure to use = the ATM calculation over an ATM-based link makes VoIP etc. less good and = fails to make CeroWrt stand out as a great solution, but it=92s the = status quo for the entire world. Or we could say, the default should be ATM so that the ATM = latency is under control again, while PTM users just sacrifice some = (considerable) amount of bandwidth :) >=20 > If the choices are as =93simple=94 as this (and please correct me if = I=92m wrong :-) we really want to find a way to encourage people to use = the ATM calculation when it=92s warranted. We could hope that they find = their way to the AQM tab (before their eyes glaze over), but that seems = too big a hurdle. So I changed the link layer tab a bit, hopefully making clearer = which link layer to select... >=20 > Perhaps we could extend the Interface configuration page to add a = =93Link uses DSL/ADSL:=94 checkbox right below the Protocol dropdown. = Default would be off, but when customers go to the GE00 interface to = enter their PPPoE/PPPoATM/ISP credentials, they=92d see this additional = checkbox. Checking it would feed that info to the AQM tab. (And perhaps = there could be a link there either to the AQM tab, or to the wiki for = more information.) I am happy to include a link to a wiki, but I guess we first = need a wiki page :)=20 Best Sebastian >=20 > Best, >=20 > Rich