From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-x430.google.com (mail-wr1-x430.google.com [IPv6:2a00:1450:4864:20::430]) (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 913843B29E for ; Mon, 26 Sep 2022 17:10:28 -0400 (EDT) Received: by mail-wr1-x430.google.com with SMTP id bq9so12124616wrb.4 for ; Mon, 26 Sep 2022 14:10:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date; bh=zohyqWTtaNCVwOeK4S+XbyyrdziCI1LTyTyEtD20Kco=; b=X/R3ZoK0cZeB9ehpl/67j+XNKKMpjPvA0rdo7DpogxdaDjc5peeTQA1HBVXaSyt258 ikWDWTcDiGC095y2+uuL6rP7ykgHgmD1u5lZ01X6o2abS6/T2Z5U/YG19YPsA/QWkiA4 vPKCxFtuvVUQRYpqKwbHe14uFw6H9ywDWPQyXnluGqAUiotuJVylCrOabnjK8szfaoMx zz244YBZXK9cq1iPKlDK6/LR8bRs8Xj64xWxfDCYDliDL56XOnvsnasW/dH8Vcg4vyHd 6CWYRPIVCoi7Y7KEZnWQfPIE1D3AgC0R3hay93Oz24ml6x0Ev3vUFzPvMj3gferwAow0 ZSUQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date; bh=zohyqWTtaNCVwOeK4S+XbyyrdziCI1LTyTyEtD20Kco=; b=ckhFNQqhsn5pQFLN3y8jCIfEn2f8qM4/zZTqwxycKpUOfQpNVN64uTZgjrheSi108I ZSgTdUEc1w1iLm6mYNFxIngQtsJVF4l0hJfgun6zv4HOnGcbnxx5HuET/rL6o6qarBlC u2cyBPuSZ5csBOGcW7ucM7nvT6bZO93kjW1j0kM5mdKOj7y88b7joKL6H/yJwgKTXuze Or1vwAiWvVvSzcF+RH6t/lCGOX4AhlgOIREANbxMl6QI/lwQMzXoeP3G5QtPcOudJhoO W+0dqnOb3xfc06c537RZI6nRriCF7HKqyO8JVee9Om/+1jwCZwssM8RGjJHxHJoEa4Py 2sQg== X-Gm-Message-State: ACrzQf3fnBUWrtX3+LpzcPEAMvVbFIERJXHsw2f7RSYytv1T/vtTtM20 qbzXMjdOukzAZlzbRWt5mTl/H4VI5gTmcI1FbQc5hxWanUw= X-Google-Smtp-Source: AMsMyM7Mh/MaReVa/Jv4fQuy2e4iCk+GwTxdVZdqINp64et2zZL95GdsFbFmKkJO7q2mgHjKvHyjPYY1S6cqGI1I6+Q= X-Received: by 2002:a05:6000:1565:b0:22c:8da7:3cf8 with SMTP id 5-20020a056000156500b0022c8da73cf8mr9417011wrz.688.1664226627215; Mon, 26 Sep 2022 14:10:27 -0700 (PDT) MIME-Version: 1.0 References: <060F7695-D48E-413C-9501-54ECC651ABEB@cable.comcast.com> <07C46DD5-7359-410E-8820-82B319944618@alum.mit.edu> <39E525B8-D356-4F76-82FF-F1F0B3183908@ieee.org> <498p2p23-on1q-op89-p518-1874r3r6rpo@ynat.uz> In-Reply-To: From: Dave Taht Date: Mon, 26 Sep 2022 14:10:13 -0700 Message-ID: To: Eugene Y Chang Cc: David Lang , Dave Taht via Starlink Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [Starlink] It's still the starlink latency... X-BeenThere: starlink@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Starlink has bufferbloat. Bad." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Sep 2022 21:10:28 -0000 I tend to cite rfc7567 (published 2015) a lot, which replaces rfc2309 (published 1992!). Thing is, long before that, I'd come to the conclusion that fair queuing was a requirement for sustaining the right throughput for low rate flows in wildly variable bandwidth. At certain places in LTE/5g/starlink networks the payload is encrypted and the header info required unavailable, and my advocacy of fq is certainly not shared by everyone. We don't know enough about the actual points of congestion in starlink to know if fq could be applied, and although aqm is a very good idea everywhere, is also largely undeployed where it would matter most. I focused my initial analysis of starlink on just uplink congestion, which I believe can be easily improved given about 20 minutes with a cross compiler for the dishy. We have a very good proof of concept as to how to improve starlinks behavior over here: https://forum.openwrt.org/t/cake-w-adaptive-bandwidth/135379/87 and ironically the same script could be run on their router as it is based on a 6 year old version of openwrt in the first place. I have plenty of data later than this ( https://docs.google.com/document/d/1puRjUVxJ6cCv-rgQ_zn-jWZU9ae0jZbFATLf4PQ= KblM/edit ) but I would like to be collecting it from at least six sites around the world. On Mon, Sep 26, 2022 at 1:54 PM Eugene Y Chang via Starlink wrote: > > Ok, we are getting into the details. I agree. > > Every node in the path has to implement this to be effective. > In fact, every node in the path has to have the same prioritization or th= e scheme becomes ineffective. > > Gene > ---------------------------------------------- > Eugene Chang > IEEE Senior Life Member > eugene.chang@ieee.org > 781-799-0233 (in Honolulu) > > > > On Sep 26, 2022, at 10:48 AM, David Lang wrote: > > software updates can do far more than just improve recovery. > > In practice, large data transfers are less sensitive to latency than smal= ler data transfers (i.e. downloading a CD image vs a video conference), sof= tware can ensure better fairness in preventing a bulk transfer from hurting= the more latency sensitive transfers. > > (the example below is not completely accurate, but I think it gets the po= int across) > > When buffers become excessivly large, you have the situation where a vide= o call is going to generate a small amount of data at a regular interval, b= ut a bulk data transfer is able to dump a huge amount of data into the buff= er instantly. > > If you just do FIFO, then you get a small chunk of video call, then sever= al seconds worth of CD transfer, followed by the next small chunk of the vi= deo call. > > But the software can prevent the one app from hogging so much of the conn= ection and let the chunk of video call in sooner, avoiding the impact to th= e real time traffic. Historically this has required the admin classify all = traffic and configure equipment to implement different treatment based on t= he classification (and this requires trust in the classification process), = the bufferbloat team has developed options (fq_codel and cake) that can ens= ure fairness between applications/servers with little or no configuration, = and no trust in other systems to properly classify their traffic. > > The one thing that Cake needs to work really well is to be able to know w= hat the data rate available is. With Starlink, this changes frequently and = cake integrated into the starlink dish/router software would be far better = than anything that can be done externally as the rate changes can be fed di= rectly into the settings (currently they are only indirectly detected) > > David Lang > > > On Mon, 26 Sep 2022, Eugene Y Chang via Starlink wrote: > > You already know this. Bufferbloat is a symptom and not the cause. Buffer= bloat grows when there are (1) periods of low or no bandwidth or (2) period= s of insufficient bandwidth (aka network congestion). > > If I understand this correctly, just a software update cannot make buffer= bloat go away. It might improve the speed of recovery (e.g. throw away all = time sensitive UDP messages). > > Gene > ---------------------------------------------- > Eugene Chang > IEEE Senior Life Member > eugene.chang@ieee.org > 781-799-0233 (in Honolulu) > > > > On Sep 26, 2022, at 10:04 AM, Bruce Perens wrote: > > Please help to explain. Here's a draft to start with: > > Starlink Performance Not Sufficient for Military Applications, Say Scient= ists > > The problem is not availability: Starlink works where nothing but another= satellite network would. It's not bandwidth, although others have question= s about sustaining bandwidth as the customer base grows. It's latency and j= itter. As load increases, latency, the time it takes for a packet to get th= rough, increases more than it should. The scientists who have fought buffer= bloat, a major cause of latency on the internet, know why. SpaceX needs to = upgrade their system to use the scientist's Open Source modifications to Li= nux to fight bufferbloat, and thus reduce latency. This is mostly just usin= g a newer version, but there are some tunable parameters. Jitter is a chang= e in the speed of getting a packet through the network during a connection,= which is inevitable in satellite networks, but will be improved by making = use of the bufferbloat-fighting software, and probably with the addition of= more satellites. > > We've done all of the work, SpaceX just needs to adopt it by upgrading th= eir software, said scientist Dave Taht. Jim Gettys, Taht's collaborator and= creator of the X Window System, chimed in: > Open Source luminary Bruce Perens said: sometimes Starlink's latency and = jitter make it inadequate to remote-control my ham radio station. But the m= ilitary is experimenting with remote-control of vehicles on the battlefield= and other applications that can be demonstrated, but won't happen at scale= without adoption of bufferbloat-fighting strategies. > > On Mon, Sep 26, 2022 at 12:59 PM Eugene Chang > wrote: > The key issue is most people don=E2=80=99t understand why latency matters= . They don=E2=80=99t see it or feel it=E2=80=99s impact. > > First, we have to help people see the symptoms of latency and how it impa= cts something they care about. > - gamers care but most people may think it is frivolous. > - musicians care but that is mostly for a hobby. > - business should care because of productivity but they don=E2=80=99t kno= w how to =E2=80=9Csee=E2=80=9D the impact. > > Second, there needs to be a =E2=80=9COMG, I have been seeing the action o= f latency all this time and never knew it! I was being shafted.=E2=80=9D On= ce you have this awakening, you can get all the press you want for free. > > Most of the time when business apps are developed, =E2=80=9Cwe=E2=80=9D h= ide the impact of poor performance (aka latency) or they hide from the disc= ussion because the developers don=E2=80=99t have a way to fix the latency. = Maybe businesses don=E2=80=99t care because any employees affected are just= considered poor performers. (In bad economic times, the poor performers ar= e just laid off.) For employees, if they happen to be at a location with ba= d latency, they don=E2=80=99t know that latency is hurting them. Unfair but= most people don=E2=80=99t know the issue is latency. > > Talking and explaining why latency is bad is not as effective as showing = why latency is bad. Showing has to be with something that has a person impa= ct. > > Gene > ----------------------------------- > Eugene Chang > eugene.chang@alum.mit.edu > +1-781-799-0233 (in Honolulu) > > > > > > On Sep 26, 2022, at 6:32 AM, Bruce Perens via Starlink > wrote: > > If you want to get attention, you can get it for free. I can place articl= es with various press if there is something interesting to say. Did this al= l through the evangelism of Open Source. All we need to do is write, sign, = and publish a statement. What they actually write is less relevant if they = publish a link to our statement. > > Right now I am concerned that the Starlink latency and jitter is going to= be a problem even for remote controlling my ham station. The US Military i= s interested in doing much more, which they have demonstrated, but I don't = see happening at scale without some technical work on the network. Being ab= le to say this isn't ready for the government's application would be an att= ention-getter. > > Thanks > > Bruce > > On Mon, Sep 26, 2022 at 9:21 AM Dave Taht via Starlink > wrote: > These days, if you want attention, you gotta buy it. A 50k half page > ad in the wapo or NYT riffing off of It's the latency, Stupid!", > signed by the kinds of luminaries we got for the fcc wifi fight, would > go a long way towards shifting the tide. > > On Mon, Sep 26, 2022 at 8:29 AM Dave Taht > wrote: > > > On Mon, Sep 26, 2022 at 8:20 AM Livingood, Jason > > wrote: > > > The awareness & understanding of latency & impact on QoE is nearly unknow= n among reporters. IMO maybe there should be some kind of background briefi= ngs for reporters - maybe like a simple YouTube video explainer that is sho= rt & high level & visual? Otherwise reporters will just continue to focus o= n what they know... > > > That's a great idea. I have visions of crashing the washington > correspondents dinner, but perhaps > there is some set of gatherings journalists regularly attend? > > > =EF=BB=BFOn 9/21/22, 14:35, "Starlink on behalf of Dave Taht via Starlink= " on behalf of starlink@lists.bufferbloat.net > wrote: > > I still find it remarkable that reporters are still missing the > meaning of the huge latencies for starlink, under load. > > > > > -- > FQ World Domination pending: https://blog.cerowrt.org/post/state_of_fq_co= del/ > Dave T=C3=A4ht CEO, TekLibre, LLC > > > > > -- > FQ World Domination pending: https://blog.cerowrt.org/post/state_of_fq_co= del/ > Dave T=C3=A4ht CEO, TekLibre, LLC > _______________________________________________ > Starlink mailing list > Starlink@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/starlink > > > -- > Bruce Perens K6BP > _______________________________________________ > Starlink mailing list > Starlink@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/starlink > > > > > -- > Bruce Perens K6BP > > > _______________________________________________ > Starlink mailing list > Starlink@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/starlink --=20 FQ World Domination pending: https://blog.cerowrt.org/post/state_of_fq_code= l/ Dave T=C3=A4ht CEO, TekLibre, LLC