From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.17.20]) (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 174FE21F1B5 for ; Tue, 18 Mar 2014 05:12:32 -0700 (PDT) Received: from hms-beagle.lan ([134.2.89.92]) by mail.gmx.com (mrgmx103) with ESMTPSA (Nemesis) id 0M0QLp-1XG3l83RUr-00uXlT; Tue, 18 Mar 2014 13:12:27 +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: <53281934.90707@etorok.net> Date: Tue, 18 Mar 2014 13:12:27 +0100 Content-Transfer-Encoding: quoted-printable Message-Id: <91F2F3A6-2DFA-4CC9-879B-28BD0A8AFBA2@gmx.de> References: <53281934.90707@etorok.net> To: =?windows-1252?Q?T=F6r=F6k_Edwin?= X-Mailer: Apple Mail (2.1510) X-Provags-ID: V03:K0:C1BHaEuxQBKUMXEB8WE7ARwtvp7UUDtoIwV/EmofYT1VYTKpkdi l32M5FdMFLuJEHjnUZqDQmgCAMmg8kh57sE6gIe9Ig6WQtNp7Z6e+d7TH78QfSm/5ny354C DwWacNTGLAX+xE8Zi6zcOTxXsOtZ0DGu2cI0+k6vcpbgkct0rsWIOZ5FU4LNsZ+zmpo61+A oqR9iQ1kh0CHDlWMFgvIw== Cc: cerowrt-devel@lists.bufferbloat.net Subject: Re: [Cerowrt-devel] cerowrt-3.10.32-9 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: Tue, 18 Mar 2014 12:12:32 -0000 Hi Edwin, On Mar 18, 2014, at 11:00 , T=F6r=F6k Edwin wrote: > On 03/16/2014 09:58 PM, Dave Taht wrote: >> Get it at: >>=20 >> http://snapon.lab.bufferbloat.net/~cero2/cerowrt/wndr/3.10.32-9/ >>=20 >> I've been running this a few days now with no problems. >=20 > Can you please add these packages: > - p910nd > - luci-app-p910nd > - wifitoggle >=20 > Just upgraded from 3.7.5-2, and it looks good so far. >=20 > I'm not sure about the SQM Link Layer Adaptation, the wiki says that I = should leave it as 'none' for Fiber, but how can I test > if that is actually the correct setting? If you know that you have per packet overhead (more than the = pure ethernet header that is handled with 'none') you should select = "ethernet with overhead" and specify the overhead on your line (be sure = to add the 14 bytes for the ethernet header as the kernel unhelpfully = forgets to take this into account when you use the link layer adjustment = method tc_stab) For ATM based systems we could use the RTT quantization effects = of the ATM cells to deduce the overhead empirically but for links with = out quantization that does not work, so I do not know how check which = overhead to specify empirically, all you could do is look at the = information you have for your link and potentially ask your ISP for more = information. Just remember the goal is to supply precise information = about the on-wire size of data packets so SQM can calculate the true = bandwidth-cost associated with each packet. BTW if anyone in the = audience knows how to measure the overhead for ethernet packets, please = chime in. =46rom your information below I would estimate: As far as I know GPON, basically is a ethernet hub solution = (with one segment shared between several customers) so there is only = typical ethernet overhead, plus potential framing and vlan tags, so if = you select "ethernet" as link layer option, you should use the following = overhead: PPP (2B), PPPoE (6B), ethernet (14B, reguired for tc_stab), = potentially VLAN (4B?), potentially ethernet frame check sequence (???B) Your ISP should be able to tell you whether he uses VLAN tags on = the bottle neck link (it does not matter whether the VLAN tags are = actually visible/existent on your end of the GPON modem) So somewhere in the 22 to 30bytes range should work. Alas the = only way to figure this out for good is to snoop packets on the fiber = segment, so realistically you need to ask your ISP, or be happy that = 22Bytes is as close to the true overhead as you can get with the = information at your hand. And the closer to the actual wire size SQMs = supplied bandwidths are the preciser the shaping works. That said it looks like each of your packets is like 8bytes = larger than the kernel assumes without link layer adjustments or roughly = 100*8/64 =3D 12.5 % for the smallest ethernet packets and 100*8/1500 =3D = 0.5% for the largest, assuming you typically use larger packets than 64 = bytes, you should not really notice whether the overhead is set = correctly or not. On principle I would recommend to use "ethernet with = overhead" but it should not make much of a difference. Especially since = you will need to cut the shaper some slack anyways, that is even with = link layer adjustments latency will be compromised unless you reduce the = bandwidths specified to SQM from the line rates=85 Best Regards Sebastian=20 >=20 > I have this setup with my ISP: > cerowrt router <---(Ethernet) ----> (ISP on premise switch for = multiple apartments) <----> (ISP device) <--- (fiber optics) ---> ISP >=20 > I connect using PPPoE, and AFAIK the ISP is using GPON. > Currently I have ~50 Mbps up/down speed, but I could upgrade to 1000 = Mbps up/down. >=20 > Thanks, > --Edwin >=20 >=20 >=20 > _______________________________________________ > Cerowrt-devel mailing list > Cerowrt-devel@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/cerowrt-devel