From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vb0-f41.google.com (mail-vb0-f41.google.com [209.85.212.41]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 7428421F107 for ; Fri, 21 Dec 2012 10:30:07 -0800 (PST) Received: by mail-vb0-f41.google.com with SMTP id l22so5526292vbn.28 for ; Fri, 21 Dec 2012 10:30:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type; bh=7eL7nd5cMYH67mD5QVOPz4uXc+HPOTnFFiHmcGx9wCg=; b=jsBEP92tz3i79J/oPDcmCrgIX8LaUYWJzTJcVng/AmLqMjdR/XIdIVnCnG9lhM/Gv3 YnvkI7x8QdKwdFYMhhLWB/1Rys8baWwo3mTB00hIis+nq84CRoERBPvWy5fPM7nIpPbK M8h6mYLonBV5wMUC0exBZjAUJcxsU9giPhXQkhgC2xb92KvTM2NIGvbqRznER8yYlY7w h2A1bF07E1Kt31+sP+VdHNO8rsRNvIg+GmUfe4Ss2wa6LEPfIIGEc/Hj2OKAYNsVy1Ei wvHNPFmh8EOCA63TnIclAIc9wZ4Cs8Tb96/UOWlMM7ahv1fcYNsNsBD48zCpUTIqSoeS v6LQ== MIME-Version: 1.0 Received: by 10.59.11.67 with SMTP id eg3mr21953456ved.31.1356114606355; Fri, 21 Dec 2012 10:30:06 -0800 (PST) Sender: gettysjim@gmail.com Received: by 10.58.116.135 with HTTP; Fri, 21 Dec 2012 10:30:06 -0800 (PST) In-Reply-To: <2lps03vacpqmtehlf4gnq634.1356112034562@email.android.com> References: <2lps03vacpqmtehlf4gnq634.1356112034562@email.android.com> Date: Fri, 21 Dec 2012 13:30:06 -0500 X-Google-Sender-Auth: Ytxj0q_HR7IZuQZxv-nzAaJg4zA Message-ID: From: Jim Gettys To: Alessandro Bolletta , Kathleen Nichols , "codel@lists.bufferbloat.net" , Dave Taht Content-Type: multipart/alternative; boundary=047d7bf0ec7262f4fa04d16109bd Subject: Re: [Codel] R: Making tests on Tp-link router powered by Openwrt svn 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: Fri, 21 Dec 2012 18:30:07 -0000 --047d7bf0ec7262f4fa04d16109bd Content-Type: text/plain; charset=ISO-8859-1 On Fri, Dec 21, 2012 at 12:51 PM, Alessandro Bolletta < alessandro@mediaspot.net> wrote: > Hi everybody, > Thanks so much for your useful help! I solved my problem by reproducing > bottleneck through HTB queues. > I tried some bandwidth rates and i saw that target must be increased if > the available bandwidth is <4mbps. 13ms is a good compromise for that > situation. > Also, i removed the switch from my testbed. > Codel works amazingly well, congratulations for the job that has been done! > I'll try to make more tests to ensure that it will be suitable for our > needs; we are building a new wireless mesh network in Italy based on a > totally new architecture and Codel could be a great improvement for queue > management on the nodes. > > Thanks again for your courtesy! > Alessandro Bolletta Kathy, So in this case, there is another packet of buffering *under* the codel queue in the HTB line discipline (which buffers one packet), plus whatever additional buffering of there may be in the device driver (where the mileage varies). So codel isn't actually dropping the head of the queue, but the second (or further) packet back, in effect. So the control law computation won't be quite right. - Jim --047d7bf0ec7262f4fa04d16109bd Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable



On Fri, Dec 21, 2012 at 12:51 PM, Alessandro Bolletta <ales= sandro@mediaspot.net> wrote:
Hi everybody,
Thanks so much for your useful help! I solved my problem by reproducing bot= tleneck through HTB queues.
I tried some bandwidth rates and i saw that target must be increased if the= available bandwidth is <4mbps. 13ms is a good compromise for that situa= tion.
Also, i removed the switch from my testbed.
Codel works amazingly well, congratulations for the job that has been done!=
I'll try to make more tests to ensure that it will be suitable for our = needs; we are building a new wireless mesh network in Italy based on a tota= lly new architecture and Codel could be a great improvement for queue manag= ement on the nodes.

Thanks again for your courtesy!
Alessandro Bolletta

Kathy,

So in this case, there is another packet of buffering *under* = the codel queue in the HTB line discipline (which buffers one packet), plus= whatever additional buffering of there may be in the device driver (where = the mileage varies).

So codel isn't actually dropping the he= ad of the queue, but the second (or further) packet back, in effect. =A0So = the control law computation won't be quite right.
=A0 = =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 - Jim


--047d7bf0ec7262f4fa04d16109bd--