Need help with USB tethering issues

I am USB tethering my iPhone hotspot to a GL-AR300Mx16 travel router. I had donwloaded all the necessary opkg files and was since my high speed mobile data plan had reached its limit, AT&T had throttled me down to 155kb or so. I began sharing the tethered connection throughout my home and was getting around 7mbps down and around 2-3 mbps up. This was great for the purposes that we used internet at our home but I began searching for ways to increase the speed. I setup the VPN (ProtonVPN) and Adblock settings and started getting around 11-12 mbps down and around 3mbps. Then I enabled SQM software uploading and hardware offloading and my connection jumped to 40mbps download and 20 mbps upload speed. I was happy with this and left it there. However, the speed randomly crashed down to 0.01 mbps and around the same for upload speed randomly after a few hours. I don’t know what happened but no matter how many reboots, resets, or reflashes I do to the router nothing changes and the speed stays in the depths. I had backups along the way before any major changes but restoring those backups did not help. The weird thing is that the speed was great with the backup configs I had and restoring those configs don’t do anything.

I cannot find any answers or topics related to my problem online but if anyone can help in anyway please help!!

P.S. I am running Openwrt-19.07.8 r11364-ef56c85848

I have also tried tethering my other phone with the hotspot limit not reached but speed remains 0.01-0.05

Your benchmark results aren't in line with expectations, so I'd be keen to blame signal reception in your area combined with slight differences in antenna orientation and other environmental factors between your tests.

While low for LTE, I'd accept this as a common base line.

This is fishy at best, no VPN will increase your throughput (bad peering might be circumvented that way, but a crude speedtest is unlikely to show that much of a difference) - neither does adblocking (the overall results might be more snappy, by avoiding to waste bandwidth on ads, but that's not an issue for a speedtest either).

Now this can't work at all. SQM can't improve your maximum throughput, it can help to reduce your lag (and that feels a lot faster for interactive usage), but to accomplish that, it actually has to artificially reduce and cap your throughput. Its impact on raw throughput is often negligible and the benefits to keep latency at bay easily outweigh the overall throughput reduction, but an improvement of a factor of four is simply impossible this way.

Based on these aspects, I'd remove OpenWrt from the equation - do the speedtests directly on your phone, to establish a new baseline (at best OpenWrt may be able to pass everything through, but the maximum possible is still defined by the abilities of your cellular modem (phone)) and optimum reception (antenna orientation). Once you know what's possible, don't touch the phone/ modem anymore - reset your OpenWrt router to its defaults and start testing again.

  • you should achieve the same values (at least very close) than running the speedtest on your phone directly, if not, there's something amiss
  • adblocking is certainly useful, but it won't improve your bulk throughput - only waste less of it on ads
  • if your ISP is competent, VPNs shouldn't improve your throughput either (but they might reduce it, due to the computational overhead they incur on the VPN encryption) - but with an incompetent or malicious ISP, you might get around bad peering issues,
  • SQM on a variable throughput link is a different can of worms, defer this until last - yes, there are approaches to that (CAKE w/ Adaptive Bandwidth - #4 by Lynx), but they come with a hefty penalty in terms of 'wasting' significant traffic for measurement purposes. If you have monthly quotas at play, you really don't want to use this. Unless you can find a relatively reliable sweetspot of minimum guaranteed bandwidth for a static SQM configuration, adaptive SQM can only (reasonably) be used on uncapped contracts (or at least high tier ones with 'more than enough' monthly data volume).
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Measurement is passive in the main solutions right now save for a bunch of ICMPs (highly tunable).

I couldn't live without CAKE on my LTE as otherwise RTTs go through the roof on medium to heavy connection use and interrupt ZOOM or Teams calls.

My 4G LTE ISP apply selective 10Mbit/s throttling on port 80 or 443 that can be circumvented using a VPN:

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I don’t know what went wrong but I went from around 40mbps to 15kbps. I spent hours and hours but can’t find the solution. It may be by the mobile company since I connected to my phone hotspot with another mobile device and the speed was more or less the same.

A fresh reboot of the router and plain tethered connection now gives no internet. I’m flabbergasted.

I don’t have a monthly quota but I have 50gb worth of high speed hotspot data and then it’s throttled to 128kb or so. I can connect via SSH tunnel my mobile cellular data which is high speed unlimited 5G with a DNS and Socks proxy but keeping that connection alive takes more maintenance than just routing my hotspot to the family

OK with 50 GiB allowance spending <- 3.7 GiB on autorate might still be a decent investment, but clearly your choice.
(Also 4 reflectors 5 times a second end up with 20 probes per second, it should be possible to reduce that somewhat without too much loss in responsiveness)

When I got up to 40mbps I had already used my data allowance and was supposed to be throttled to 128kb…

I don’t know if I fried my router or what but I’m still lost haha

This seems to be a different issue. My concern here is more, assuming your ISP would be competent and actually throttle as indicated in the contract, would you be willing to "invest" 3.7 GiB of your 50 GiB per month to keep latency under load lower? Or put differently how much measurement traffic volume would you accept?

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Yes I would be willing to invest 3.7Gb to get it working again. I would sacrifice 10Gbs if I have to.

Have you tried random stuff like different APN and changing TTL? Some report differences with that?

What happens if you move the phone/travelrouter combination to a different location, ideally on a different antenna-tower?
Also what happens if you run a speedtest?

I have done TTL in the firewall settings and nothing changes. I don’t know how to do any APN type configs but I am willing to try if you can’t point me in the right direction.

One thing I noticed was that checking my mobile carrier bill for this month, the hotspot and corresponding data usage was logged so I did not do something correctly I am presuming.


I literally couldn’t even access the web version but this should tell you something

When I initially reached 38-40mbps the router was laying flat next to my desk then I mounted it against the wall about 2 feet away and it was still the same speed but crashed soon thereafter. are you suggesting I use a a wifi sniffer type app to check for an ideal location? Do you really think that it would make a drastic difference?

The speed shown when running the test at shows a very quick spike up to around 25mbps then comes back down to 0.01-0.09 and keeps bouncing in that range. It kind of looks like it’s holding the speed back like throttling in a sense and it won’t let it break that range.

This is comparable to when I just connect to the WiFi on my MacBook it will be fast for about one second then crawl

At least your ISP does not special case speedtests to look better :wink:

So can you try tethering from a different location? Not that your mobile carrier tries to discourage use as home internet access?

Thats a good point. I will try to tether when I am back in the city and lets see if its the location.

Side note: I have one iPhone running a SSH server tethering its unlimited mobile data to a network I created on my MacBook to which others within the home can connect and use. But is there a way to get that type of setup where my family can connect to the router instead of the network on my Mac?

If your ISP is not playing dirty tricks or your home cell suddenly got massively congested, changing the location should not change things... (modulo things like the modem not using the ideal frequency band for your tower).

I would guess yes. You would need to figure out how to "tether" your iphone to your router. I would think that should work. But I have zero first hand experience (being a user of cheapish android phones, iphones are above my pay-grade) and so will not attempt to speculate on the how-to.