From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) (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 C9C883B29E for ; Mon, 26 Sep 2022 17:35:57 -0400 (EDT) Received: by mail-pj1-x1030.google.com with SMTP id q35-20020a17090a752600b002038d8a68fbso13840583pjk.0 for ; Mon, 26 Sep 2022 14:35:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ieee.org; s=google; h=references:to:cc:in-reply-to:date:subject:mime-version:message-id :from:from:to:cc:subject:date; bh=kzzD1k3pIdmwgwdM8ou580ky/joz372Wljp4nGvHpKA=; b=EiZToVm8Gc5RKMQTMZKFu/1nI/fNX5iywVPMUUKmlEtfOuWYGApJbnGbnNlRCrRITw //p40cMNGCtA0vUMU5a5S5BZa4fMxWj46g4+EZYdCRtm0YQv1ArDbMt7rjLnzAM5/Ic2 J9/Eh7AXYKB94rTn1U/ze1wC2pqOQpAK4hcjg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=references:to:cc:in-reply-to:date:subject:mime-version:message-id :from:x-gm-message-state:from:to:cc:subject:date; bh=kzzD1k3pIdmwgwdM8ou580ky/joz372Wljp4nGvHpKA=; b=MKl6+/joEJuImMfkFLz7oL0pJsKznJxkgAtgNHRLK7au2xNwRLT1HxkSTgVVCW8En9 S2zbu9iWF1zJ7GUjBCyyGTaYrQ6IJ4WitQ9pWcD+EEHEwdl/4LU3aqkav6SrT4j155JD 79HQPtqoP6jepNS+BkmoXInbYXBDN18goIap2oRnvDQcSaJeZOsWevIjNWH2jeQ+TYGR KDV5u05az/o8Fpp59UaiWm0wBiquuJ3giaNFhr7YqvviZVGgpmkxIHnd0Im/dqDZwwKJ RcOPDEPLLx5hp+O7k7cgNNoPHxhNHZA7fXrTpHAs16PEboI+HR9RyUSgI/49KBzLJbLl K7Eg== X-Gm-Message-State: ACrzQf1rKGN+NeLPXihJVIgume9DtlFIBNQ/UA8gQgeV1/KJGKCLTeNP +bKGoieJIcNEuaWpA9tmH2zaRYe04CArA0Bk X-Google-Smtp-Source: AMsMyM7C7V4CXZfjyIPFdXgXlEafGXSIai7KdOB/JpP/ROp2Mp5K2aTjwswc4XR4wR5jIaLRtfm0OQ== X-Received: by 2002:a17:90b:2bc3:b0:204:f748:5cc2 with SMTP id ru3-20020a17090b2bc300b00204f7485cc2mr843016pjb.80.1664228156397; Mon, 26 Sep 2022 14:35:56 -0700 (PDT) Received: from smtpclient.apple (dhcp-72-253-196-65.hawaiiantel.net. [72.253.196.65]) by smtp.gmail.com with ESMTPSA id t14-20020a17090a510e00b002005c3d4d4fsm6878406pjh.19.2022.09.26.14.35.55 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 26 Sep 2022 14:35:55 -0700 (PDT) From: Eugene Y Chang Message-Id: Content-Type: multipart/signed; boundary="Apple-Mail=_9732B718-85C1-4279-BB0B-7870985C7DFE"; protocol="application/pgp-signature"; micalg=pgp-sha256 Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3696.120.41.1.1\)) Date: Mon, 26 Sep 2022 11:35:53 -1000 In-Reply-To: <9D97FB02-58A5-48B0-9B43-6B7BD2A24099@gmx.de> Cc: Eugene Chang , David Lang , Dave Taht via Starlink To: Sebastian Moeller 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> <8DC6E5EE-2B46-4815-A909-E326507E95B1@ieee.org> <9D97FB02-58A5-48B0-9B43-6B7BD2A24099@gmx.de> X-Mailer: Apple Mail (2.3696.120.41.1.1) 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 21:36:01 -0000 --Apple-Mail=_9732B718-85C1-4279-BB0B-7870985C7DFE Content-Type: multipart/alternative; boundary="Apple-Mail=_0C0A33A0-6C2A-4A9D-93C7-B47272B624A9" --Apple-Mail=_0C0A33A0-6C2A-4A9D-93C7-B47272B624A9 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Thank you for the dialog,. This discussion with regards to Starlink is interesting as it confirms = my guesses about the gap between Starlinks overly simplified, over = optimistic marketing and the reality as they acquire subscribers. I am actually interested in a more perverse issue. I am seeing latency = and bufferbloat as a consequence from significant under provisioning. It = doesn=E2=80=99t matter that the ISP is selling a fiber drop, if (parts) = of their network is under provisioned. Two end points can be less than 5 = mile apart and realize 120+ ms latency. Two Labor Days ago (a holiday) = the max latency was 230+ ms. The pattern I see suggest digital = redlining. The older communities appear to have much more severe under = provisioning. Another observation. Running speedtest appears to go from the edge of = the network by layer 2 to the speedtest host operated by the ISP. Yup, = bypasses the (suspected overloaded) routers. Anyway, just observing. Gene ---------------------------------------------- Eugene Chang IEEE Senior Life Member eugene.chang@ieee.org 781-799-0233 (in Honolulu) > On Sep 26, 2022, at 11:20 AM, Sebastian Moeller = wrote: >=20 > Hi Gene, >=20 >=20 >> On Sep 26, 2022, at 23:10, Eugene Y Chang = wrote: >>=20 >> Comments inline below. >>=20 >> Gene >> ---------------------------------------------- >> Eugene Chang >> IEEE Senior Life Member >> eugene.chang@ieee.org >> 781-799-0233 (in Honolulu) >>=20 >>=20 >>=20 >>> On Sep 26, 2022, at 11:01 AM, Sebastian Moeller = wrote: >>>=20 >>> Hi Eugene, >>>=20 >>>=20 >>>> On Sep 26, 2022, at 22:54, Eugene Y Chang via Starlink = wrote: >>>>=20 >>>> Ok, we are getting into the details. I agree. >>>>=20 >>>> Every node in the path has to implement this to be effective. >>>=20 >>> Amazingly the biggest bang for the buck is gotten by fixing = those nodes that actually contain a network path's bottleneck. Often = these are pretty stable. So yes for fully guaranteed service quality all = nodes would need to participate, but for improving things noticeably it = is sufficient to improve the usual bottlenecks, e.g. for many internet = access links the home gateway is a decent point to implement better = buffer management. (In short the problem are over-sized and = under-managed buffers, and one of the best solution is better/smarter = buffer management). >>>=20 >>=20 >> This is not completely true. >=20 > [SM] You are likely right, trying to summarize things leads to = partially incorrect generalizations. >=20 >=20 >> Say the bottleneck is at node N. During the period of congestion, the = upstream node N-1 will have to buffer. When node N recovers, the = bufferbloat at N-1 will be blocking until the bufferbloat drains. Etc. = etc. Making node N better will reduce the extent of the backup at N-1, = but N-1 should implement the better code. >=20 > [SM] It is the node that builds up the queue that profits most = from better queue management.... (again I generalize, the node with the = queue itself probably does not care all that much, but the endpoints = will profit if the queue experiencing node deals with that queue more = gracefully). >=20 >=20 >>=20 >>=20 >>>=20 >>>> In fact, every node in the path has to have the same prioritization = or the scheme becomes ineffective. >>>=20 >>> Yes and no, one of the clearest winners has been flow queueing, = IMHO not because it is the most optimal capacity sharing scheme, but = because it is the least pessimal scheme, allowing all (or none) flows = forward progress. You can interpret that as a scheme in which flows = below their capacity share are prioritized, but I am not sure that is = the best way to look at these things. >>=20 >> The hardest part is getting competing ISPs to implement and = coordinate. >=20 > [SM] Yes, but it turned out even with non-cooperating ISPs there = is a lot end-users can do unilaterally on their side to improve both = ingress and egress congestion. Admittedly especially ingress congestion = would be even better handled with cooperation of the ISP. >=20 >> Bufferbloat and handoff between ISPs will be hard. The only way to = fix this is to get the unwashed public to care. Then they can say =E2=80=9C= we don=E2=80=99t care about the technical issues, just fix it.=E2=80=9D = Until then =E2=80=A6.. >=20 > [SM] Well we do this one home network at a time (not because = that is efficient or ideal, but simply because it is possible). Maybe, = if you have not done so already try OpenWrt with sqm-scripts (and maybe = cake-autorate in addition) on your home internet access link for say a = week and let us know ih/how your experience changed? >=20 > Regards > Sebastian >=20 >=20 >>=20 >>=20 >>=20 >>>=20 >>> Regards >>> Sebastian >>>=20 >>>=20 >>>>=20 >>>> Gene >>>> ---------------------------------------------- >>>> Eugene Chang >>>> IEEE Senior Life Member >>>> eugene.chang@ieee.org >>>> 781-799-0233 (in Honolulu) >>>>=20 >>>>=20 >>>>=20 >>>>> On Sep 26, 2022, at 10:48 AM, David Lang wrote: >>>>>=20 >>>>> software updates can do far more than just improve recovery. >>>>>=20 >>>>> In practice, large data transfers are less sensitive to latency = than smaller data transfers (i.e. downloading a CD image vs a video = conference), software can ensure better fairness in preventing a bulk = transfer from hurting the more latency sensitive transfers. >>>>>=20 >>>>> (the example below is not completely accurate, but I think it gets = the point across) >>>>>=20 >>>>> When buffers become excessivly large, you have the situation where = a video call is going to generate a small amount of data at a regular = interval, but a bulk data transfer is able to dump a huge amount of data = into the buffer instantly. >>>>>=20 >>>>> If you just do FIFO, then you get a small chunk of video call, = then several seconds worth of CD transfer, followed by the next small = chunk of the video call. >>>>>=20 >>>>> But the software can prevent the one app from hogging so much of = the connection and let the chunk of video call in sooner, avoiding the = impact to the real time traffic. Historically this has required the = admin classify all traffic and configure equipment to implement = different treatment based on the classification (and this requires trust = in the classification process), the bufferbloat team has developed = options (fq_codel and cake) that can ensure fairness between = applications/servers with little or no configuration, and no trust in = other systems to properly classify their traffic. >>>>>=20 >>>>> The one thing that Cake needs to work really well is to be able to = know what 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 directly into the settings (currently they are = only indirectly detected) >>>>>=20 >>>>> David Lang >>>>>=20 >>>>>=20 >>>>> On Mon, 26 Sep 2022, Eugene Y Chang via Starlink wrote: >>>>>=20 >>>>>> You already know this. Bufferbloat is a symptom and not the = cause. Bufferbloat grows when there are (1) periods of low or no = bandwidth or (2) periods of insufficient bandwidth (aka network = congestion). >>>>>>=20 >>>>>> If I understand this correctly, just a software update cannot = make bufferbloat go away. It might improve the speed of recovery (e.g. = throw away all time sensitive UDP messages). >>>>>>=20 >>>>>> Gene >>>>>> ---------------------------------------------- >>>>>> Eugene Chang >>>>>> IEEE Senior Life Member >>>>>> eugene.chang@ieee.org >>>>>> 781-799-0233 (in Honolulu) >>>>>>=20 >>>>>>=20 >>>>>>=20 >>>>>>> On Sep 26, 2022, at 10:04 AM, Bruce Perens = wrote: >>>>>>>=20 >>>>>>> Please help to explain. Here's a draft to start with: >>>>>>>=20 >>>>>>> Starlink Performance Not Sufficient for Military Applications, = Say Scientists >>>>>>>=20 >>>>>>> The problem is not availability: Starlink works where nothing = but another satellite network would. It's not bandwidth, although others = have questions about sustaining bandwidth as the customer base grows. = It's latency and jitter. As load increases, latency, the time it takes = for a packet to get through, increases more than it should. The = scientists who have fought bufferbloat, 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 Linux to fight bufferbloat, and = thus reduce latency. This is mostly just using a newer version, but = there are some tunable parameters. Jitter is a change 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. >>>>>>>=20 >>>>>>> We've done all of the work, SpaceX just needs to adopt it by = upgrading their 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 military 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. >>>>>>>=20 >>>>>>> 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. >>>>>>>=20 >>>>>>> First, we have to help people see the symptoms of latency and = how it impacts 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=99= t know how to =E2=80=9Csee=E2=80=9D the impact. >>>>>>>=20 >>>>>>> Second, there needs to be a =E2=80=9COMG, I have been seeing the = action of latency all this time and never knew it! I was being = shafted.=E2=80=9D Once you have this awakening, you can get all the = press you want for free. >>>>>>>=20 >>>>>>> Most of the time when business apps are developed, =E2=80=9Cwe=E2=80= =9D hide the impact of poor performance (aka latency) or they hide from = the discussion 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 are just laid off.) For employees, if they happen to = be at a location with bad 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. >>>>>>>=20 >>>>>>> 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 impact. >>>>>>>=20 >>>>>>> Gene >>>>>>> ----------------------------------- >>>>>>> Eugene Chang >>>>>>> eugene.chang@alum.mit.edu >>>>>>> +1-781-799-0233 (in Honolulu) >>>>>>>=20 >>>>>>>=20 >>>>>>>=20 >>>>>>>=20 >>>>>>>=20 >>>>>>>> On Sep 26, 2022, at 6:32 AM, Bruce Perens via Starlink = > = wrote: >>>>>>>>=20 >>>>>>>> If you want to get attention, you can get it for free. I can = place articles with various press if there is something interesting to = say. Did this all 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. >>>>>>>>=20 >>>>>>>> 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 is 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 able to say this isn't ready for the = government's application would be an attention-getter. >>>>>>>>=20 >>>>>>>> Thanks >>>>>>>>=20 >>>>>>>> Bruce >>>>>>>>=20 >>>>>>>> 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. >>>>>>>>=20 >>>>>>>> On Mon, Sep 26, 2022 at 8:29 AM Dave Taht > wrote: >>>>>>>>>=20 >>>>>>>>> On Mon, Sep 26, 2022 at 8:20 AM Livingood, Jason >>>>>>>>> > wrote: >>>>>>>>>>=20 >>>>>>>>>> The awareness & understanding of latency & impact on QoE is = nearly unknown among reporters. IMO maybe there should be some kind of = background briefings for reporters - maybe like a simple YouTube video = explainer that is short & high level & visual? Otherwise reporters will = just continue to focus on what they know... >>>>>>>>>=20 >>>>>>>>> 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? >>>>>>>>>=20 >>>>>>>>>>=20 >>>>>>>>>> =EF=BB=BFOn 9/21/22, 14:35, "Starlink on behalf of Dave Taht = via Starlink" on behalf of = starlink@lists.bufferbloat.net > = wrote: >>>>>>>>>>=20 >>>>>>>>>> I still find it remarkable that reporters are still missing = the >>>>>>>>>> meaning of the huge latencies for starlink, under load. >>>>>>>>>>=20 >>>>>>>>>>=20 >>>>>>>>>=20 >>>>>>>>>=20 >>>>>>>>> -- >>>>>>>>> FQ World Domination pending: = https://blog.cerowrt.org/post/state_of_fq_codel/ >>>>>>>>> Dave T=C3=A4ht CEO, TekLibre, LLC >>>>>>>>=20 >>>>>>>>=20 >>>>>>>>=20 >>>>>>>> -- >>>>>>>> FQ World Domination pending: = https://blog.cerowrt.org/post/state_of_fq_codel/ >>>>>>>> Dave T=C3=A4ht CEO, TekLibre, LLC >>>>>>>> _______________________________________________ >>>>>>>> Starlink mailing list >>>>>>>> Starlink@lists.bufferbloat.net = >>>>>>>> https://lists.bufferbloat.net/listinfo/starlink = >>>>>>>>=20 >>>>>>>>=20 >>>>>>>> -- >>>>>>>> Bruce Perens K6BP >>>>>>>> _______________________________________________ >>>>>>>> Starlink mailing list >>>>>>>> Starlink@lists.bufferbloat.net = >>>>>>>> https://lists.bufferbloat.net/listinfo/starlink = >>>>>>>=20 >>>>>>>=20 >>>>>>>=20 >>>>>>> -- >>>>>>> Bruce Perens K6BP >>>>=20 >>>> _______________________________________________ >>>> Starlink mailing list >>>> Starlink@lists.bufferbloat.net >>>> https://lists.bufferbloat.net/listinfo/starlink --Apple-Mail=_0C0A33A0-6C2A-4A9D-93C7-B47272B624A9 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 Thank= you for the dialog,.
This discussion with regards to = Starlink is interesting as it confirms my guesses about the gap between = Starlinks overly simplified, over optimistic marketing and the reality = as they acquire subscribers.

I am actually interested in a more = perverse issue. I am seeing latency and bufferbloat as a consequence = from significant under provisioning. It doesn=E2=80=99t matter that the = ISP is selling a fiber drop, if (parts) of their network is under = provisioned. Two end points can be less than 5 mile apart and realize = 120+ ms latency. Two Labor Days ago (a holiday) the max latency was 230+ = ms. The pattern I see suggest digital redlining. The older communities = appear to have much more severe under provisioning. 

Another observation. = Running speedtest appears to go from the edge of the network by layer 2 = to the speedtest host operated by the ISP. Yup, bypasses the (suspected = overloaded) routers.

Anyway, just observing.

Gene
----------------------------------------------
Eugene Chang
IEEE Senior Life = Member
eugene.chang@ieee.org
781-799-0233 (in = Honolulu)



On Sep 26, 2022, at 11:20 AM, Sebastian Moeller <moeller0@gmx.de> = wrote:

Hi Gene,


On Sep 26, 2022, at 23:10, Eugene Y = Chang <eugene.chang@ieee.org> wrote:

Comments inline below.

Gene
----------------------------------------------
Eugene Chang
IEEE Senior Life Member
eugene.chang@ieee.org
781-799-0233 (in = Honolulu)



On Sep 26, 2022, at = 11:01 AM, Sebastian Moeller <moeller0@gmx.de> wrote:

Hi Eugene,


On Sep 26, 2022, at = 22:54, Eugene Y Chang via Starlink = <starlink@lists.bufferbloat.net> wrote:

Ok, we are getting into the details. I agree.
Every node in the path has to implement this to be = effective.

Amazingly = the biggest bang for the buck is gotten by fixing those nodes that = actually contain a network path's bottleneck. Often these are pretty = stable. So yes for fully guaranteed service quality all nodes would need = to participate, but for improving things noticeably it is sufficient to = improve the usual bottlenecks, e.g. for many internet access links the = home gateway is a decent point to implement better buffer management. = (In short the problem are over-sized and under-managed buffers, and one = of the best solution is better/smarter buffer management).


This is not = completely true.

= [SM] You are = likely right, trying to summarize things leads to partially incorrect = generalizations.


Say the bottleneck is at node N. = During the period of congestion, the upstream node N-1 will have to = buffer. When node N recovers, the bufferbloat at N-1 will be blocking = until the bufferbloat drains. Etc. etc.  Making node N better will = reduce the extent of the backup at N-1, but N-1 should implement the = better code.

= [SM] It is = the node that builds up the queue that profits most from better queue = management.... (again I generalize, the node with the queue itself = probably does not care all that much, but the endpoints will profit if = the queue experiencing node deals with that queue more = gracefully).





In fact, every node in = the path has to have the same prioritization or the scheme becomes = ineffective.

Yes and = no, one of the clearest winners has been flow queueing, IMHO not because = it is the most optimal capacity sharing scheme, but because it is the = least pessimal scheme, allowing all (or none) flows forward progress. = You can interpret that as a scheme in which flows below their capacity = share are prioritized, but I am not sure that is the best way to look at = these things.

The hardest part = is getting competing ISPs to implement and coordinate. 

= [SM] Yes, but = it turned out even with non-cooperating ISPs there is a lot end-users = can do unilaterally on their side to improve both ingress and egress = congestion. Admittedly especially ingress congestion would be even = better handled with cooperation of the ISP.

Bufferbloat and handoff between ISPs will be hard. The only = way to fix this is to get the unwashed public to care. Then they can say = =E2=80=9Cwe don=E2=80=99t care about the technical issues, just fix = it.=E2=80=9D Until then =E2=80=A6..

[SM] Well we do this one home network at a time (not because = that is efficient or ideal, but simply because it is possible). Maybe, = if you have not done so already try OpenWrt with sqm-scripts (and maybe = cake-autorate in addition) on your home internet access link for say a = week and let us know ih/how your experience changed?

Regards
= Sebastian






Regards
= Sebastian



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 <david@lang.hm> wrote:

software updates can do far more than just improve = recovery.

In practice, large data transfers = are less sensitive to latency than smaller data transfers (i.e. = downloading a CD image vs a video conference), software 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 point = across)

When buffers become excessivly = large, you have the situation where a video call is going to generate a = small amount of data at a regular interval, but a bulk data transfer is = able to dump a huge amount of data into the buffer instantly.

If you just do FIFO, then you get a small = chunk of video call, then several seconds worth of CD transfer, followed = by the next small chunk of the video call.

But the software can prevent the one app from hogging so much = of the connection and let the chunk of video call in sooner, avoiding = the impact to the real time traffic. Historically this has required the = admin classify all traffic and configure equipment to implement = different treatment based on the classification (and this requires trust = in the classification process), the bufferbloat team has developed = options (fq_codel and cake) that can ensure 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 what 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 directly 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. Bufferbloat grows when there = are (1) periods of low or no bandwidth or (2) periods of insufficient = bandwidth (aka network congestion).

If I = understand this correctly, just a software update cannot make = bufferbloat 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 <bruce@perens.com> wrote:

Please help to explain. Here's a draft to start with:

Starlink Performance Not Sufficient for = Military Applications, Say Scientists

The = problem is not availability: Starlink works where nothing but another = satellite network would. It's not bandwidth, although others have = questions about sustaining bandwidth as the customer base grows. It's = latency and jitter. As load increases, latency, the time it takes for a = packet to get through, increases more than it should. The scientists who = have fought bufferbloat, 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 Linux to fight bufferbloat, and thus reduce = latency. This is mostly just using a newer version, but there are some = tunable parameters. Jitter is a change 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 their software, said = scientist Dave Taht. Jim Gettys, Taht's collaborator and creator of the = X Window System, chimed in: <fill in here please>
Open= Source luminary Bruce Perens said: sometimes Starlink's latency and = jitter make it inadequate to remote-control my ham radio station. But = the military 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 = <eugene.chang@alum.mit.edu<mailto:eugene.chang@alum.mit.edu>> = 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 impacts 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 know 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 of latency all this time and never knew it! = I was being shafted.=E2=80=9D Once 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 hide the = impact of poor performance (aka latency) or they hide from the = discussion 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 are just laid off.) For employees, if they happen to = be at a location with bad 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 impact.

Gene
-----------------------------------
Eugene Chang
eugene.chang@alum.mit.edu = <mailto:eugene.chang@alum.mit.edu>
+1-781-799-0233 = (in Honolulu)





On Sep 26, 2022, at 6:32 AM, Bruce Perens via Starlink = <starlink@lists.bufferbloat.net<mailto:starlink@lists.bufferbloat.ne= t>> wrote:

If you want to get = attention, you can get it for free. I can place articles with various = press if there is something interesting to say. Did this all 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 is = 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 = able to say this isn't ready for the government's application would be = an attention-getter.

 Thanks

 Bruce

On = Mon, Sep 26, 2022 at 9:21 AM Dave Taht via Starlink = <starlink@lists.bufferbloat.net<mailto:starlink@lists.bufferbloat.ne= t>> 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 <dave.taht@gmail.com = <mailto:dave.taht@gmail.com>> wrote:

On Mon, Sep 26, 2022 at 8:20 AM = Livingood, Jason
<Jason_Livingood@comcast.com = <mailto:Jason_Livingood@comcast.com>> wrote:

The = awareness & understanding of latency & impact on QoE is nearly = unknown among reporters. IMO maybe there should be some kind of = background briefings for reporters - maybe like a simple YouTube video = explainer that is short & high level & visual? Otherwise = reporters will just continue to focus on 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" = <starlink-bounces@lists.bufferbloat.net = <mailto:starlink-bounces@lists.bufferbloat.net> on behalf of = starlink@lists.bufferbloat.net = <mailto: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_codel/<https://blog.cerowrt.o= rg/post/state_of_fq_codel/>
Dave T=C3=A4ht CEO, = TekLibre, LLC


--
FQ World Domination pending: = https://blog.cerowrt.org/post/state_of_fq_codel/<https://blog.cerowrt.o= rg/post/state_of_fq_codel/>
Dave T=C3=A4ht CEO, = TekLibre, LLC
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--
Bruce Perens K6BP
_______________________________________________
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https://lists.bufferbloat.net/listinfo/starlink = <https://lists.bufferbloat.net/listinfo/starlink>



--Bruce Perens K6BP

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