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Comment by Tarball10 | Hacker News Reader

AT&T uses different APNs for regular phone plans and data-only hotspot plans. It's very possible that the phone traffic is being routed completely differently than the hotspot traffic, with congestion at a peering point occurring on the hotspot. AT&T tends to be known for having poor/congested peering.

You could try changing the DNS server on your hotspot to a different public resolver like 1.1.1.1 or 8.8.8.8. If CloudFront is using DNS based geolocation to route you to the nearest data center, a different DNS server may get you routed around the issue to a different data center.

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Use resolvers that support eDNS Client Subnet, otherwise geo-resolvers like Google/CF DNS may cause your traffic to be misrouted.

You can use Quad9's EDNS [0] so your client is properly routed, any privacy concerns aside.

[0] https://www.quad9.net/support/faq/#edns

Quad9 doesn't work on AT&T, because of poor routing you're sent to Miami or Amsterdam.

Good tip. I just tried with both and wasn't routed to a faster point of presence with either.

I'll add a traceroute from the phone and one from a device connected to the LTE router to the updates section next.

[update] Traceroutes added

It's definitely odd that you're getting routed across the country to an east coast pop. Ideally in your location you'd be routed to a west or central pop. Perhaps a bad combination of Cloudfront getting geolocation wrong for your IP range, and poor performance of at&t's network for that specific source-destination combination.

I found that odd as well, and my iPhone hotspot does get routed through a different list of hosts as you can see in the traceroute.

I suppose it should be noted. The iphone antenna and router antennas are no more than a meter from each other. They're unlikely to be hitting different towers.

What are you using for DNS?

On chrome-based mobile browsers your traceroutes are getting stuck in a small non scrollable iframe-type-thing.

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