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[71.241.215.163]) by mx.google.com with ESMTPSA id 59sm1449500qgf.37.2015.04.10.05.15.05 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 10 Apr 2015 05:15:05 -0700 (PDT) Content-Type: multipart/signed; boundary="Apple-Mail=_2B0F761A-2839-46AB-849E-39E446583825"; protocol="application/pgp-signature"; micalg=pgp-sha512 Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) From: Rich Brown In-Reply-To: <9A8B9375-C683-4A85-9D65-564AEECE1300@gmail.com> Date: Fri, 10 Apr 2015 08:14:48 -0400 Message-Id: References: <2E760E83-7224-4B9B-B918-B3EAD578E831@gmail.com> <67BE685A-724C-45D7-A619-EC49498AF165@gmail.com> <9A8B9375-C683-4A85-9D65-564AEECE1300@gmail.com> To: Jonathan Morton X-Mailer: Apple Mail (2.1878.6) Cc: cerowrt-devel , bloat Subject: Re: [Cerowrt-devel] [Bloat] Questions about the use of HTB & fq_codel in simple.qos, simplest.qos 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: Fri, 10 Apr 2015 12:15:37 -0000 --Apple-Mail=_2B0F761A-2839-46AB-849E-39E446583825 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 Hi Jonathan, Thanks for the response - this is really helpful. As I said in my = original note, I'm casting about for usable advice that we can offer to = people today. I want it to be unarguably true, and I want to understand = the nuances so that I don't get tripped up by Gotcha's.=20 I'm currently focussed on OpenWrt, as that's a platform where it's easy = to roll out fq_codel in current builds simply by downloading a couple = packages. I'll work on a draft note with recommendations for OpenWrt and = send it past the list for comments. Thanks again. Rich On Apr 9, 2015, at 6:02 PM, Jonathan Morton = wrote: >=20 >> On 10 Apr, 2015, at 00:35, Rich Brown = wrote: >>=20 >> - Why do we provide an HTB-based shaper in simple.qos and = simplest.qos? >> - Do the shapers in these sqm-scripts actually limit bandwidth for = various kinds of traffic? Might that not leave unused bandwidth? >> - Or do they just shunt certain packets to higher or lower priority = fq_codel tiers/bands/levels (terminology used in Dave's note below)? >> - And if the latter, how does the "link" (I'm not sure of the proper = term) know which of the tiers/bands/levels to dequeue next? >=20 > The short answer is: because cake isn=92t out in the real world yet. = We=92re working on it. >=20 > HTB and IFB as used in those scripts is a stopgap solution, to take = control of the bottleneck queue so that fq_codel can work on it. Cake = includes a shaper which does the job more effectively and more = efficiently. >=20 > Ultimately, what we=92d like is for fq_codel (or even something as = sophisticated as cake) to be implemented in the *actual* bottleneck = queues, so that artificially taking control of the bottleneck isn=92t = necessary. >=20 >> I'll state up front that I'm not entirely clear on the distinction = between shapers, qdisc's, IFBs, etc. But I'm groping around for a = simple, clear recommendation for what we should tell people to do so = they can: >> a) Make their router work very well, with minimal latency >> b) Spend their time more usefully than tweaking QoS/priority = settings (for example, by actually playing the game that whose lag = you're trying to minimize :-) >=20 > If they=92ve got a router with the sqm-scripts installed, use those = and follow the directions. The implementation is a little messy, but it = works and it keeps things simple for the user. >=20 > When cake arrives, the implementation will get simpler and more = efficient. >=20 > - Jonathan Morton >=20 --Apple-Mail=_2B0F761A-2839-46AB-849E-39E446583825 Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP using GPGMail -----BEGIN PGP SIGNATURE----- Comment: GPGTools - https://gpgtools.org iQEcBAEBCgAGBQJVJ76+AAoJEH4agC/0z73/VksH/A8DDOcDzylLND6Jsq1vuLLg InCzA/UGz5IEHVzZBEjuzDeN3psfnuIf9UYkIrVZipB1yJmKmInbzKUD4GSGNIMe ETaqgLDP/BhBLIHMJQOCNvtiqikBD44R5NNUxJtQ4g2Z9cVFaUhdcHcn3fkGyFCb BVnVE+OqS/QakAXdh+wCChDzWTEVZkXqL2xfH9PSzVYEV6LqVBZfKGnMUnjG/oll UihATAFEsQBTq1DvfRz/VqR3YLuQVUTbPvgfS79JhZHfqS3s9x2vHp1xVgcY5oA2 Cpd4w6BLDLhyAGCi51ygmIRzf2cjTsJr8Smn8pmtS9H/Fg5VwMQbLn3URn9KHWI= =UPBY -----END PGP SIGNATURE----- --Apple-Mail=_2B0F761A-2839-46AB-849E-39E446583825--