Ask HN: Internet magically gets faster when opening speedtest? • Hacker News Board

So Occam’s Razor makes me doubt it. ISPs do all kinds of tricks to make speed tests work well, co-locating, prioritising that path etc. But I don’t think they’ve complex profiling equipment that slows everything, then removes the slowdown when they see DNS/SNI for speedtest, then apply it again after.

Also been working for ISPs for 20+ years and never heard of it. Only exception may be in cellular with their fancy PCRF boxes, but even there I think it’s much more common to throttle one class, and not another, than to slow everything but switch the throttle on/off if you access a particular site.

If this is true you could easily game it by running speed test all the time. All you gotta do is throttle bandwidth to the speed test servers yourself somehow (so the speed test goes slow and doesn’t eat your available bandwidth.) Then you’ll be permanently in the “they’re doing speedtest give them full speed” category.

Re: Ask HN: Internet magically gets faster when opening speedtest?

#313

Post by revanx_ » Mon, Apr 18, 2022, 11:07 AM UTC

dataflow wrote: post #139

traceroute66 wrote: post #36

Lots of people here have already mentioned the Netflix fast.com test, which is indeed good. But also worthy of recommendation IHMO is the Cloudflare one (speed.cloudflare.com). Main reason I say that is its one of the few that measures jitter (or at least openly exposes the measurement).

CloudFlare one is giving me less than 1/3 the download speed fast.com shows, and in fact, testing by downloading a Linux ISO [1], the latter seems to be the correct one. I don't know what CloudFlare's test is doing (their server is geographically nearby) but I obviously can't trust their measurement. [1] https://mirrors.edge.kernel.org/archlinux/iso/2022.04.05/arc...

for me download is correct but upload is 1/3 ...

Re: Ask HN: Internet magically gets faster when opening speedtest?

#314

Post by exikyut » Mon, Apr 18, 2022, 11:08 AM UTC

zinekeller wrote: post #302

exikyut wrote: post #276

Earlier quoted context omitted.

You mean you told the PHY to renegotiate at 10M with something like `ethtool -s speed 10`? While stumbling around attempting to figure out `tc qdisc` a while back I found that the shaping it was applying was very synthetic, such that asking for low bitrate and high latency would mean the kernel would just wait a second or two then shunt several KB of data through at once. IIRC I was just playing with the default appr…

Ah, apologies for not responding here. It's (shocks in disgust) a Realtek one, I forgot which specifically, but the "smart" switch (ugh, I hate the naming everything smart) definitely said that it's only a 10M Ethernet connection. Using Chrome's limiter, capped at 5,000,000 bits/sec (5Mbps) both direction: Speedtest.net: 5.00Mbps in both directions (nice, are they're including overhead in these calculations?) Cloudfl…

All good - realtek aren't that bad at the end of the day, I'm running my internet connection through a 100M ADMtek card from ~2004 :D

Well it probably was 10M then. The port LED on the switch might've changed color as well. (Smart reminds me of the consumer-lite answer to SDN.)

I just tried fast.com myself using 100kbps and it quite happily measured at line rate (6.8M+800k, yay D:). For some bizarre reason I found I needed to open a new tab, open the devtools, set the network speed, then load fast.com for it to work. My guess is that Chrome applies connection ratelimiting metadata as new connections are created, such that existing sockets still in keepalive aren't affected. I'd say that's at least a documentation bug.

I'm not really able/sure how to reproduce the other comment I linked (using an actual 10M switch and seeing 100M of throughput). That's really interesting.

Re: Ask HN: Internet magically gets faster when opening speedtest?

#315

Post by MinorTom » Mon, Apr 18, 2022, 11:13 AM UTC

dataflow wrote: post #200

FrenchDevRemote wrote: post #197

Earlier quoted context omitted.

That's probably due to your ISP imo, they're known to favor some routes/servers Or the cabling to the cloudfare server is worse than to other servers

My ISP is unlikely to be a problem. I literally get higher speeds downloading from servers across the world in Australia [1] than from CloudFlare's benchmark. Something around CF's side is funny, not mine. I'm looking at the network tab, it seems like they send a ton of small requests instead of a large one... which might point in the direction of the problem. [1] https://syd.mirror.rackspace.com/archlinux/iso/2022.0…

The issue is likely not with Cloudflare, but with the connection between your ISP and Cloudflare. That's why this speed test is relevant - if your ISP can't manage to make good, settlement free* connections (=peering) to Cf it's not a good ISP.

Example: Rackspace Sydney (AS58683) has (likely paid) peering with AS7474, who has peering with German Deutsche Telekom (AS3320). Peering with DT is significantly more expensive than many others because they have a regional monopoly.

* Cloudflare is present at many regional Internet Exchanges and any good ISP connects to these, too. Some don't, however, like Deutsche Telekom.

Re: Ask HN: Internet magically gets faster when opening speedtest?

#316

Post by dataflow » Mon, Apr 18, 2022, 11:19 AM UTC

MinorTom wrote: post #315

dataflow wrote: post #200

Earlier quoted context omitted.

My ISP is unlikely to be a problem. I literally get higher speeds downloading from servers across the world in Australia [1] than from CloudFlare's benchmark. Something around CF's side is funny, not mine. I'm looking at the network tab, it seems like they send a ton of small requests instead of a large one... which might point in the direction of the problem. [1] https://syd.mirror.rackspace.com/archlinux/iso/2022.0…

The issue is likely not with Cloudflare, but with the connection between your ISP and Cloudflare. That's why this speed test is relevant - if your ISP can't manage to make good, settlement free* connections (=peering) to Cf it's not a good ISP. Example: Rackspace Sydney (AS58683) has (likely paid) peering with AS7474, who has peering with German Deutsche Telekom (AS3320). Peering with DT is significantly more expensi…

When CloudFlare is the odd one out having trouble with people's ISPs (just read other people's comments right here about their experiences with that benchmark... I'm not exactly the only one getting weird results) and when my ISP isn't having the same trouble when connecting to other servers across the world, blaming my ISP is... weird. It's a little bit like driving on the other side of the highway and then blaming everyone else for driving the wrong way. But I mean, if you still prefer to blame everyone but CF, by all means feel free.

Re: Ask HN: Internet magically gets faster when opening speedtest?

#317

Post by tssva » Mon, Apr 18, 2022, 11:27 AM UTC

300bps wrote: post #238

zffr wrote: post #218

Earlier quoted context omitted.

I’m not sure why, but I’m seeing 1mbps on fast.com, and 20mbps on speedtest.net. Weird how there’s such a huge difference

Are you on mobile? Some mobile providers limit streaming quality and they do this by limiting bandwidth to streaming providers. For example, Visible will never be faster than 2 Mbps to fast.com. You’ll get faster on Speedtest.net because it doesn’t throttle non-video related sites.

I almost forgot Visible limits video streaming. My phone has an always on Wireguard VPN connection to my home which prevents Visible from limiting streaming. Just tested. From my current location, which doesn't have the best signal, with the VPN on I get 66Mbps to fast.com and with it off 2.1Mbps.

Re: Ask HN: Internet magically gets faster when opening speedtest?

#318

Post by quantum2021 » Mon, Apr 18, 2022, 11:33 AM UTC

hackernewds wrote: post #212

serenitylater wrote: post #166

Earlier quoted context omitted.

You can have plenty of projects get done that take longer than 4 years. You will have problems getting projects done that half the country hates if it takes longer than 4 years. This seems like a feature not a bug.

something half the country hates can be good for the whole country. think COVID vaccines and lockdowns

Like the lockdowns did jack. Just look at the numbers and the spread of the virus with lockdowns in place. Hell, look at the Chinese in lockdown still today. Lockdowns were all political and crushed a huge portion of this country that the one voting party didn't like.

Re: Ask HN: Internet magically gets faster when opening speedtest?

#319

Post by Solaerum » Mon, Apr 18, 2022, 12:10 PM UTC

No post body was provided.

Re: Ask HN: Internet magically gets faster when opening speedtest?

#320

Post by Solaerum » Mon, Apr 18, 2022, 12:11 PM UTC

Download a steam game and check your speeds...