From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-x234.google.com (mail-wm0-x234.google.com [IPv6:2a00:1450:400c:c09::234]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id B71063B25E for ; Thu, 9 Jun 2016 20:49:08 -0400 (EDT) Received: by mail-wm0-x234.google.com with SMTP id k204so81633164wmk.0 for ; Thu, 09 Jun 2016 17:49:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:to:references:cc:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding; bh=jZMX3w5sLm1cICndU33XUXs+gjtezd07cC8MU9u+RYY=; b=K6VxcHb+5WVLriw8y/RnlXyvFjEHuPRcCosavDKb4HAaq1Kc1+7MmpFC4KsIqA8UJH pcAGZ6PlWwaA2d87vUKjPe0ACBIVcklzKtE7SKWGD9EhJI+JCVKg2UWKCnUvaD7CAeYt mMPSJ/+vqWYCZc42PA8S8Xt9z6KlJfpu3frEMVlr4U7065Nky1ncPxwHs12CQzYCXd+M AOKMdQ4fa32bDFiiTem5JQW5mbeFG/M3LcN5nI95NyU8i1aEjUmLHGenadWeddW/ShC6 qRY5CYkOGiMkt1x9wSb6SLvNuMqV1LRbjyqYLVJA6Vt7lBMJI6WcGGkyMXyhtIWZSWi2 MBDQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:subject:to:references:cc:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding; bh=jZMX3w5sLm1cICndU33XUXs+gjtezd07cC8MU9u+RYY=; b=GZ42D5N6+vOBEEbg/dz2XwBDIDVOS5sWUz4Q45yNcqHp7AjoqOuEBOh3dz3G626EDt n2UtvI5sr/YX+oePEPH6eMzvYkFrVAECMjDWpVohq7naNekHa6hHaTfaVykz9f8FGncd bBWyVLQdTxygYaEIdvq3o6POwP6sCrbq72soTa53gzF7nI5mICCwaDdkP+7IwZ8u9S8n nMiuCbIna27C8GZIKjWemVrtgeDTpCDWVvswCDtU31RTBjo+e0TdA/GMgomjkKoqO/VA kb16PKjUbQw8A6ePPeLB6M1XSVeTlI31MbkScrGagSixAyvAerxL/RpNeWhvI+1huYPm Unxg== X-Gm-Message-State: ALyK8tK0II3liXClz6OPLdOYS4zYOkzuwQo9/NdJayX3/i8BjBKkL4Gxc3gaDjJi/5LEdw== X-Received: by 10.194.5.129 with SMTP id s1mr12487180wjs.96.1465519747559; Thu, 09 Jun 2016 17:49:07 -0700 (PDT) Received: from [192.168.0.1] (ip-109-90-29-200.hsi11.unitymediagroup.de. [109.90.29.200]) by smtp.gmail.com with ESMTPSA id m7sm10210686wma.10.2016.06.09.17.49.06 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 09 Jun 2016 17:49:07 -0700 (PDT) To: moeller0 References: <7409a52d-8c81-25f0-e070-c7638fdf9d83@gmail.com> <0B4652E3-F061-479D-8BB3-EA0193333A51@gmx.de> Cc: cake@lists.bufferbloat.net From: Dennis Fedtke Message-ID: <3d4cdbf4-42dd-a371-2d44-f1bad6505684@gmail.com> Date: Fri, 10 Jun 2016 02:49:06 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.1.1 MIME-Version: 1.0 In-Reply-To: <0B4652E3-F061-479D-8BB3-EA0193333A51@gmx.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable Subject: Re: [Cake] New to cake. Some questions X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 10 Jun 2016 00:49:09 -0000 Hi Sebastian, Sorry this is positive or? But i need more samples ? Thanks :) Am 10.06.2016 um 01:11 schrieb moeller0: > Hi Dennis, > >> On Jun 10, 2016, at 00:45 , Dennis Fedtke wro= te: >> >> Hi Sebastian, >> >> thank you for your answers :) >> >> The ATM overhead detector script is currently running. >> I read the wiki about it but im not quite sure how to interpret the pl= ot. >> I mean what info should i read from it? maximum packet size? > The relevant number is reported as =E2=80=9CEstimated overhead precedi= ng the IP header=E2=80=9D in the top part of the second figure created by= the script. But that is only relevant.useful if you see a nice step like= plot in figure 2 as well ( the second figure in https://github.com/moell= er0/ATM_overhead_detector/wiki as positive and the fourth figure as negat= ive example. > >> If yes do i set the overhead in cake? Or do i set iptables to clamp to= new mtu/mss? > If you use plain cake and you know the numerical overhead (NN) the eas= iest is to add the following to your cake invocation: =E2=80=9Catm overhe= ad NN=E2=80=9D > > Please note that if you use cake on an ethernet interface the kernel wi= ll already account for 14 byte of ethernet overhead, so if the script tol= d you 44 as actual overhead, you use =E2=80=9Doverhead 30=E2=80=9D to add= ress that. If you use a pppoe interface the kernel will most likely not a= dd the 14 bytes for you, so then you would use =E2=80=9Coverhead 44=E2=80= =9D (I excluded the atm option in the last examples for clarity=E2=80=A6)= > >> Regarding UDP paket dropping problem: >> I just read some forums and users stated that under heavy load cake st= arts to drop udp packets which causes lag ingame. >> My idea was to set ingress/egress to diffserv4 and apply the EF dscp m= ark on those packets. > Ell, not a bad idea, but often the problem are in the incoming traffic= , and unfortunately with the ifb we use we can not use iptables, but only= tc, and remarking with tc is unpleasant. > >> Will this even work? if yes how to do this? iptables? > No, you wuld need tp use tc. > >> ipt -t mangle -A PREROUTING -p udp -m multiport --ports 5000:5500 -j D= SCP --set-dscp-class EF >> >> Like thia? Is prerouting correct here? (Taken from layer cake script) > This will affect outgoing packets and might be a good idea in your spe= cific case. > > BUT why don=E2=80=99t you try the default behaviour with specific rules= and tricks and report success or failure back to us, after all the faste= st/easiest classification is one one does not need to perform at all. > >> >> For the squash and wash feature. >> Im asking because if i choose to squash in the advanced options of sqm= scripts. >> The dscp fields/marks will be overwritten by iptables to 0 (besteffort= ). (layer cake script) >> So then it makes no sense to manually set dscp fields/marks or? (Or ev= en setting diffserv) > No unfortunately on ingress cake sees the packets before iptables, so = the effective behavioral emulation of wash/squash by cake is to set ingre= ss cake to besteffort (basically cake ignores the dscp field which functi= onally is identical to all packets having the same value). The squashing = by iptables just clears the dscp marls so that internal networking elemen= ts like potentially wifi liknks are not confuzed by the dscp information.= > >> Did i understand this correctly. Per rfc isps should not provide dscp = fields/marks? > Not exactly, per RFC DSCPs are only ever valid/defined inside a DSCP d= omain and your ISPs domain ends before it reaches your CPE. Since you hav= e no control over your ISPs markings, they can be very much not like you = want them to be (Dave That reported that his ISP re-mapped almost 1/3 or = so of packets into the CS1 background class). So it is recomended that ea= ch DSCP domain re-mapps the code points at its entry point, which in your= case is your router=E2=80=A6 > > Best Regards > Sebastian > >> >> Thank you. >> >> >> >> Am 09.06.2016 um 23:30 schrieb moeller0: >>> Hi Dennis, >>> >>> let me start with a disclaimer, I am not the best information source = for cake on this mailing list, but I assume the others will chime in if I= say something questionable=E2=80=A6 >>> >>>> On Jun 9, 2016, at 22:58 , Dennis Fedtke wr= ote: >>>> >>>> Hi >>>> >>>> Currently im running lede + cake + sqm_scripts and i have some quest= ions: >>>> >>>> 1. What is considered the =E2=80=9Coptimal" setup atm for cake? >>> The same as without cake; really, proper per-packet-overhead account= ing is important for bandwidth shaping, especially for ATM -based links. = I would recommend to follow the method on https://github.com/moeller0/ATM= _overhead_detector to m\empirically measure whether your link uses ATM en= capsulation and what exact overhead is in use. >>> >>>> e.g. which cake script should i use piece or layer cake? >>> piece_of_cake has only one tier of priority, while layer_cake curren= tly offers 4. Packets are put into the different priority bands based on = the content of their TOS/DSCP filed in the IP header; if this is greek to= you, I guess piece_of_cake most likely is what you are looking for.. >>> >>>> 2. Recently squash and wash was removed. >>>> But the sqm scripts were not updated. In the advanced options should= i set that the dcsp marks are kept? >>> This really is an implementation detail that has no immediate effect= if you choose piece_of_cake as typically only the bottleneck is sensitiv= e to DSCP based priority banding. (Typically in that if you are unlucky y= our WLAN will use the DSCP marks to move packets into 4 different priorit= y classes, which is fine if you want that, but bad for not sanity checked= packets coming in from the wider internet (one is not supposed to assume= incoming packets have sensible dscp markings as per RFC) that is why the= wash/squash option is missed by some of us, independent of the fact that= it was a layering violation). >>> >>>> 3. Should i use advanced options in sqm scripts and set triple-isola= te + diffserv8 ? >>> If you understand what these options do and believe that this is the= best for your network go ahead, otherwise=E2=80=A6 The triple-isolate op= tion will try to be fair to host_IP addresses first and then for each hos= tIP fair to each flow, but for that to do something you will most likely = want this requires that cake sees internal IP addresses of your end-hosts= =2E In the typical configuration with SQM on the WAN interface of a NAT r= outer all internal addresses are replaced with the external IP address of= the router it self and triple-isolates per host fairness will pretty muc= h be equal to per flow fairness (not exactly, but in essence). So if you = want to try tiple-isolate or its better defined brothers dual-srchost and= dual-dsthost you would need to instantiate SQM on an internal interface = like LAN. But then the direction of ingress and egress from the routers p= erspective changes with regards to the internet download and upload direc= tion and you will need to put the internet upload bandwidth into the down= load field of the sqm GUI and vice versa. Also SQM on an internal interfa= ce will also shape internal traffic over the same interface, and that oft= en affects traffic to and from the wifi/wlan radios to the lan switch=E2=80= =A6 (I guess you would have preferred a shorter less vague response, but = such are the constraints=E2=80=A6) >>> >>>> 4. Is it recommend to enable diffserv on ingress? >>> If you trust/konw/have confirmed that your upstream (ISP?) sends you= sensible and reasonable DSCP markings by all means enable diffserv on in= gress. But the default assumption should be that your upstream used a dsc= p mapping that only makes sense for them and not for you. >>> >>>> 5. Is there still the udp packet dropping problem? e.g. games that a= re using udp. >>>> If yes does it make sense to apply diffserv classes manually? How to= do this? >>> I am not sure what you mean, but if you test this and have some find= ings please report here=E2=80=A6 >>> >>>> 6. is the autorate_ingress still under development? >>>> This very interesting feature. especially for docsis networks. Will = it be possible to set target ping time? >>> The last tests did indicate that this feature is not ready for prime= time at least not on typically fixed bandwidth links and I assume docsis = links are fixed enough. >>> >>>> 6. What difference does it make to set a different rtt? >>>> Setting lower rtt will reduce download speed i guess but will it all= ow better ping times (because of lower downloadrate uh)? >>>> What happens if rtt is set way higher? >>> With the RTT parameter you in essence specify how much time you give= the endpoints of a flow to respond to a congestion signal (ECN marking o= r packet drop) if you select this way to small you will sacrifice bandwid= th, if you set this too high you will accumulate more latency under load.= The good thing seems to be that this does not need to be terribly precis= e, order of magnitude correctness seems to be sufficient (at least in bas= e2) >>> >>> >>>> Thank you! >>> I am sure the real experts will also chime in=E2=80=A6 >>> >>> Best Regards >>> Sebastian >>> >>>> _______________________________________________ >>>> Cake mailing list >>>> Cake@lists.bufferbloat.net >>>> https://lists.bufferbloat.net/listinfo/cake >> >> _______________________________________________ >> Cake mailing list >> Cake@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/cake