[Starlink] insanely great waveform result for starlink

Dave Taht dave.taht at gmail.com
Fri Jan 13 15:49:59 EST 2023 

On Fri, Jan 13, 2023 at 12:30 PM Nathan Owens <nathan at nathan.io> wrote:

> Here's the data visualization for Johnathan's Data
>
> [image: Screenshot 2023-01-13 at 12.29.15 PM.png]
>
> You can see the path change at :12, :27, :42, :57 after the minute. Some
> paths are clearly busier than others with increased loss, latency, and
> jitter.
>

I am so glad to see loss and bounded delay here. Also a bit of rigor
regarding what traffic was active locally vs on the path would be nice,
although it seems to line up with the known 15s starlink switchover thing
(need a name for this), in this case, doing a few speedtests
while that irtt is running would show the impact(s) of whatever else they
are up to.

It would also be my hope that the loss distribution in the middle portion
of this data is good, not bursty, but we don't have a tool to take apart
that. (I am so hopeless at json)



>
>
> On Fri, Jan 13, 2023 at 10:09 AM Nathan Owens <nathan at nathan.io> wrote:
>
>> I’ll run my visualization code on this result this afternoon and report
>> back!
>>
>> On Fri, Jan 13, 2023 at 9:41 AM Jonathan Bennett via Starlink <
>> starlink at lists.bufferbloat.net> wrote:
>>
>>> The irtt command, run with normal, light usage:
>>> https://drive.google.com/file/d/1SiVCiUYnx7nDTxIVOY5w-z20S2O059rA/view?usp=share_link
>>>
>>> Jonathan Bennett
>>> Hackaday.com
>>>
>>>
>>> On Fri, Jan 13, 2023 at 11:26 AM Dave Taht <dave.taht at gmail.com> wrote:
>>>
>>>> packet caps would be nice... all this is very exciting news.
>>>>
>>>> I'd so love for one or more of y'all reporting such great uplink
>>>> results nowadays to duplicate and re-plot the original irtt tests we
>>>> did:
>>>>
>>>> irtt client -i3ms -d300s myclosestservertoyou.starlink.taht.net -o
>>>> whatever.json
>>>>
>>>> They MUST have changed their scheduling to get such amazing uplink
>>>> results, in addition to better queue management.
>>>>
>>>> (for the record, my servers are de, london, fremont, sydney, dallas,
>>>> newark, atlanta, singapore, mumbai)
>>>>
>>>> There's an R and gnuplot script for plotting that output around here
>>>> somewhere (I have largely personally put down the starlink project,
>>>> loaning out mine) - that went by on this list... I should have written
>>>> a blog entry so I can find that stuff again.
>>>>
>>>> On Fri, Jan 13, 2023 at 9:02 AM Jonathan Bennett via Starlink
>>>> <starlink at lists.bufferbloat.net> wrote:
>>>> >
>>>> >
>>>> > On Fri, Jan 13, 2023 at 6:28 AM Ulrich Speidel via Starlink <
>>>> starlink at lists.bufferbloat.net> wrote:
>>>> >>
>>>> >> On 13/01/2023 6:13 pm, Ulrich Speidel wrote:
>>>> >> >
>>>> >> > From Auckland, New Zealand, using a roaming subscription, it puts
>>>> me
>>>> >> > in touch with a server 2000 km away. OK then:
>>>> >> >
>>>> >> >
>>>> >> > IP address: nix six.
>>>> >> >
>>>> >> > My thoughts shall follow later.
>>>> >>
>>>> >> OK, so here we go.
>>>> >>
>>>> >> I'm always a bit skeptical when it comes to speed tests - they're
>>>> really
>>>> >> laden with so many caveats that it's not funny. I took our new work
>>>> >> Starlink kit home in December to give it a try and the other day
>>>> finally
>>>> >> got around to set it up. It's on a roaming subscription because our
>>>> >> badly built-up campus really isn't ideal in terms of a clear view of
>>>> the
>>>> >> sky. Oh - and did I mention that I used the Starlink Ethernet
>>>> adapter,
>>>> >> not the WiFi?
>>>> >>
>>>> >> Caveat 1: Location, location. I live in a place where the best
>>>> Starlink
>>>> >> promises is about 1/3 in terms of data rate you can actually get from
>>>> >> fibre to the home at under half of Starlink's price. Read: There are
>>>> few
>>>> >> Starlink users around. I might be the only one in my suburb.
>>>> >>
>>>> >> Caveat 2: Auckland has three Starlink gateways close by: Clevedon
>>>> (which
>>>> >> is at a stretch daytrip cycling distance from here), Te Hana and
>>>> Puwera,
>>>> >> the most distant of the three and about 130 km away from me as the
>>>> crow
>>>> >> flies. Read: My dishy can use any satellite that any of these three
>>>> can
>>>> >> see, and then depending on where I put it and how much of the
>>>> southern
>>>> >> sky it can see, maybe also the one in Hinds, 840 km away, although
>>>> that
>>>> >> is obviously stretching it a bit. Either way, that's plenty of
>>>> options
>>>> >> for my bits to travel without needing a lot of handovers. Why? Easy:
>>>> If
>>>> >> your nearest teleport is close by, then the set of satellites that
>>>> the
>>>> >> teleport can see and the set that you can see is almost the same, so
>>>> you
>>>> >> can essentially stick with the same satellite while it's in view for
>>>> you
>>>> >> because it'll also be in view for the teleport. Pretty much any bird
>>>> >> above you will do.
>>>> >>
>>>> >> And because I don't get a lot of competition from other users in my
>>>> area
>>>> >> vying for one of the few available satellites that can see both us
>>>> and
>>>> >> the teleport, this is about as good as it gets at 37S latitude. If
>>>> I'd
>>>> >> want it any better, I'd have to move a lot further south.
>>>> >>
>>>> >> It'd be interesting to hear from Jonathan what the availability of
>>>> home
>>>> >> broadband is like in the Dallas area. I note that it's at a lower
>>>> >> latitude (33N) than Auckland, but the difference isn't huge. I notice
>>>> >> two teleports each about 160 km away, which is also not too bad. I
>>>> also
>>>> >> note Starlink availability in the area is restricted at the moment -
>>>> >> oversubscribed? But if Jonathan gets good data rates, then that means
>>>> >> that competition for bird capacity can't be too bad - for whatever
>>>> reason.
>>>> >
>>>> > I'm in Southwest Oklahoma, but Dallas is the nearby Starlink gateway.
>>>> In cities, like Dallas, and Lawton where I live, there are good broadband
>>>> options. But there are also many people that live outside cities, and the
>>>> options are much worse. The low density userbase in rural Oklahoma and
>>>> Texas is probably ideal conditions for Starlink.
>>>> >>
>>>> >>
>>>> >> Caveat 3: Backhaul. There isn't just one queue between me and
>>>> whatever I
>>>> >> talk to in terms of my communications. Traceroute shows about 10 hops
>>>> >> between me and the University of Auckland via Starlink. That's 10
>>>> >> queues, not one. Many of them will have cross traffic. So it's a bit
>>>> >> hard to tell where our packets really get to wait or where they get
>>>> >> dropped. The insidious bit here is that a lot of them will be
>>>> between 1
>>>> >> Gb/s and 10 Gb/s links, and with a bit of cross traffic, they can all
>>>> >> turn into bottlenecks. This isn't like a narrowband GEO link of a few
>>>> >> Mb/s where it's obvious where the dominant long latency bottleneck in
>>>> >> your TCP connection's path is. Read: It's pretty hard to tell
>>>> whether a
>>>> >> drop in "speed" is due to a performance issue in the Starlink system
>>>> or
>>>> >> somewhere between Starlink's systems and the target system.
>>>> >>
>>>> >> I see RTTs here between 20 ms and 250 ms, where the physical latency
>>>> >> should be under 15 ms. So there's clearly a bit of buffer here along
>>>> the
>>>> >> chain that occasionally fills up.
>>>> >>
>>>> >> Caveat 4: Handovers. Handover between birds and teleports is
>>>> inevitably
>>>> >> associated with a change in RTT and in most cases also available
>>>> >> bandwidth. Plus your packets now arrive at a new queue on a new
>>>> >> satellite while your TCP is still trying to respond to whatever it
>>>> >> thought the queue on the previous bird was doing. Read: Whatever your
>>>> >> cwnd is immediately after a handover, it's probably not what it
>>>> should be.
>>>> >>
>>>> >> I ran a somewhat hamstrung (sky view restricted) set of four Ookla
>>>> >> speedtest.net tests each to five local servers. Average upload rate
>>>> was
>>>> >> 13 Mb/s, average down 75.5 Mb/s. Upload to the server of the ISP that
>>>> >> Starlink seems to be buying its local connectivity from (Vocus Group)
>>>> >> varied between 3.04 and 14.38 Mb/s, download between 23.33 and 52.22
>>>> >> Mb/s, with RTTs between 37 and 56 ms not correlating well to rates
>>>> >> observed. In fact, they were the ISP with consistently the worst
>>>> rates.
>>>> >>
>>>> >> Another ISP (MyRepublic) scored between 11.81 and 21.81 Mb/s up and
>>>> >> between 106.5 and 183.8 Mb/s down, again with RTTs badly correlating
>>>> >> with rates. Average RTT was the same as for Vocus.
>>>> >>
>>>> >> Note the variation though: More or less a factor of two between
>>>> highest
>>>> >> and lowest rates for each ISP. Did MyRepublic just get lucky in my
>>>> >> tests? Or is there something systematic behind this? Way too few
>>>> tests
>>>> >> to tell.
>>>> >>
>>>> >> What these tests do is establish a ballpark.
>>>> >>
>>>> >> I'm currently repeating tests with dish placed on a trestle closer to
>>>> >> the heavens. This seems to have translated into fewer outages / ping
>>>> >> losses (around 1/4 of what I had yesterday with dishy on the ground
>>>> on
>>>> >> my deck). Still good enough for a lengthy video Skype call with my
>>>> folks
>>>> >> in Germany, although they did comment about reduced video quality.
>>>> But
>>>> >> maybe that was the lighting or the different background as I wasn't
>>>> in
>>>> >> my usual spot with my laptop when I called them.
>>>> >
>>>> > Clear view of the sky is king for Starlink reliability. I've got my
>>>> dishy mounted on the back fence, looking up over an empty field, so it's
>>>> pretty much best-case scenario here.
>>>> >>
>>>> >>
>>>> >> --
>>>> >>
>>>> >> ****************************************************************
>>>> >> Dr. Ulrich Speidel
>>>> >>
>>>> >> School of Computer Science
>>>> >>
>>>> >> Room 303S.594 (City Campus)
>>>> >>
>>>> >> The University of Auckland
>>>> >> u.speidel at auckland.ac.nz
>>>> >> http://www.cs.auckland.ac.nz/~ulrich/
>>>> >> ****************************************************************
>>>> >>
>>>> >>
>>>> >>
>>>> >> _______________________________________________
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>>>> >> Starlink at lists.bufferbloat.net
>>>> >> https://lists.bufferbloat.net/listinfo/starlink
>>>> >
>>>> > _______________________________________________
>>>> > Starlink mailing list
>>>> > Starlink at lists.bufferbloat.net
>>>> > https://lists.bufferbloat.net/listinfo/starlink
>>>>
>>>>
>>>>
>>>> --
>>>> This song goes out to all the folk that thought Stadia would work:
>>>>
>>>> https://www.linkedin.com/posts/dtaht_the-mushroom-song-activity-6981366665607352320-FXtz
>>>> Dave Täht CEO, TekLibre, LLC
>>>>
>>> _______________________________________________
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>>> Starlink at lists.bufferbloat.net
>>> https://lists.bufferbloat.net/listinfo/starlink
>>>
>>

-- 
This song goes out to all the folk that thought Stadia would work:
https://www.linkedin.com/posts/dtaht_the-mushroom-song-activity-6981366665607352320-FXtz
Dave Täht CEO, TekLibre, LLC
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