From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-we0-x229.google.com (mail-we0-x229.google.com [IPv6:2a00:1450:400c:c03::229]) (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 03AFA21F1E3 for ; Mon, 25 Nov 2013 10:32:04 -0800 (PST) Received: by mail-we0-f169.google.com with SMTP id t60so4339836wes.28 for ; Mon, 25 Nov 2013 10:32:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=B4NmL66UWQZHClzeng5eXONFMYysoV9q3/LIrrC8+YU=; b=n11Sk7eGWlvwO6mdiSSHBUXTLdh0EIzgLtJsvDzvMI+3SYjr4hPwMeV3VMDz5AO7WK sRmUmM5s4+57/1MAt2IWRnE+0iQx3iZ4F/pacK/KrPSLoeXsc9bnJX6LrurxIi32uMWa 07H+0ne2cc2UPDJ0e/WrgoVRlBU7rkDI6cHJWqhNSxjgk9uEdp7/hDHvmM8YL6u3lLzH B7ySThJ51W3u9TT47P7yNvYmcivvKdTnonqeP42VIekaEQ+csvHrCf4Q6w/APlb0ZS65 nRvx4k+GFs9ZqO2J0S0UGFoX9teXblCg3GYe+5zTYHTkBMSS07ID0RIviwXfVzxMzmnG BJtA== MIME-Version: 1.0 X-Received: by 10.180.74.52 with SMTP id q20mr15092600wiv.60.1385404323293; Mon, 25 Nov 2013 10:32:03 -0800 (PST) Received: by 10.217.51.5 with HTTP; Mon, 25 Nov 2013 10:32:03 -0800 (PST) In-Reply-To: References: Date: Mon, 25 Nov 2013 10:32:03 -0800 Message-ID: From: Dave Taht To: Alessandro Bolletta Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: "codel@lists.bufferbloat.net" Subject: Re: [Codel] R: Jumbo frames with fq_codel X-BeenThere: codel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: CoDel AQM discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 25 Nov 2013 18:32:05 -0000 On Mon, Nov 25, 2013 at 10:17 AM, Alessandro Bolletta wrote: >>On Mon, Nov 25, 2013 at 10:02 AM, Alessandro Bolletta wrote: >> Hi guys, >> I'm working on an environment which runs on jumbo ethernet frames (about= 1550bytes) and I would ask you if do you think that it's needed >a trick i= n order to correctly debloat interfaces as ath9k and ag71xx which carries s= uch big frames. > >>I am under the impression that the ag71xx does not support jumbo frames. >>Slightly larger than usual frames? dunno. > > We are thinking to implement jumbo frames support on some devices based o= n ag71xx :) > Many SoCs support up to 2028 bytes or 4076 bytes of MTU but the driver st= ill can't manage MTUs higher than 1518bytes. > >>the ath9k supports frames up to the size of the wireless standards (23xx = bytes or so) > > Yes. > >>fq_codel's internal quantum is the actual ip packet size, not the wire si= ze. >>at lower bandwidths it pays to have a lower quantum (like 300) on outgoin= g interfaces. > >>In openwrt the default on all interfaces is 300, which I dont necessarily= agree with. > > Ok. I thought that codel would leverage on layer-2 parameters, as the siz= e of the ethernet frame. One of the beauties of codel is it doesn't care the size of the frame at all, it only cares about how long it takes to deliver it. Now, there are some interesting interactions between codel delivering a big fat TSO string of packets and then a smaller packet (collatoral damage), but they aren't bad, and there's fixes in 3.12 for tso that make life saner. fq_codel's quantum controls the degree of mixing between flows, set it really low (say 300) to help voip and acks out on slow asymmetric links, don't set it lower, otherwise leave it alone. >> >> Thanks >> >> -- >> Alessandro Bolletta >> Mediaspot S.r.l. >> >> >> _______________________________________________ >> Codel mailing list >> Codel@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/codel > > > > -- > Dave T=E4ht > > Fixing bufferbloat with cerowrt: http://www.teklibre.com/cerowrt/subscrib= e.html > > > _______________________________________________ > Codel mailing list > Codel@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/codel --=20 Dave T=E4ht Fixing bufferbloat with cerowrt: http://www.teklibre.com/cerowrt/subscribe.= html