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I know something about this. I built and ran a service for carriers to help with “WiFi offload”. It’s intended as a consumer-friendly way to increase capacity

I know something about this. I built and ran a service for carriers to help with “WiFi offload”. It’s intended as a consumer-friendly way to increase capacity in dense areas (like a sports stadium or mall) where the carrier’s cell towers don’t have enough capacity. Wifi offloading is not new. AT&T helped invent these standards back in ~2009 when their network was getting crushed by massive increases in traffic as iPhone usage took off. WiFi offload networks are configured as “Managed Networks” which are lower priority than any user-selected networks. You can disable them by turning off “auto-join”. (Also these WiFi offload networks are secure; you can’t spoof them). However it appears that the original poster’s carrier (presumably Xfinity Mobile or Spectrum Mobile) has done something new - they’ve disabled the user’s ability to turn off “auto-join” on iOS. Some overzealous team is trying to lower their cellular costs. That’s because both Comcast and Spectrum rent capacity on Verizon Wireless towers, but their MVNO cellular service is not profitable unless their customers are using the cable company’s own WiFi fairly often. However this (disabling “auto-join”) is a dumb move. It’s obviously problematic for users whose neighbors are broadcasting the [Xfinity WiFi or Spectrum Mobile?] SSID. To my knowledge, no major carrier does this. If you’re on AT&T, T-Mobile, or Verizon, the “managed offload networks” can be easily disabled. And the major carriers are using higher-quality commercial WiFi networks for offload, not random home cable modems.

sholladay 3y ago
Confirmed. I’m on one of the major carriers and after multiple hours, auto-join is still disabled after I turned it off. Though, I haven’t tried rebooting.
- hk1337 3y ago
  I’m in the same boat as you. It’s been off for almost 24 hours and I rebooted my device. I’m not using an eSIM like OP maybe that’s the difference, I don’t think so. I wonder if those with the problem were to restart or reset their device, if they would still have the problem?
divan 3y ago
Thanks for explanation. > they’ve disabled the user’s ability to turn off “auto-join” on iOS How (and why) is it even possible for carriers?
- seraphsf 3y ago
  Frankly, I don’t know. This thread is the first I’ve heard of it. Carriers ask phone makers for config changes all the time. It’s possible this is a new capability that was requested by certain carriers. To be fair, it’s also possible that the OP and I are misinterpreting what’s going on. For instance, iOS syncs your preferences across devices. Perhaps there’s some bug that’s causing the wrong setting to propagate back to this person’s phone because their iPads, etc are still set to allow “auto join”.
  - stacktrust 3y ago
    > iOS syncs your preferences across devices. This theory could be tested by signing out of iCloud before changing "auto-join".
- webmobdev 3y ago
  > How (and why) is it even possible for carriers? This happened in India. So one day mobile data was quite slow on my non-Apple phone. I asked my friend to enable hotspot on his iPhone. We were stumped when we couldn't find the "Personal Hotspot" option at all in ios settings. Called Apple support who informed us that Hotspot option is only available if the carrier enables it. They asked us to contact the carrier. We were outraged and thought the carriers in India had suddenly decided to charge us extra for this option. Or maybe just for iPhone users. (In india, no carrier charges us extra for this option - and that is how it should be right? We are already paying more according to the bandwidth (3g/4g/5g speeds) and they also already limit how much data we can download. Imagine being charged extra for the "privilege" of sharing your data and consuming it faster!). We were prepared to yell at the carrier if they wanted more money from us for this but their customer support explained to us that this is a common complain they have with Apple iPhones, and all we needed to do was add some more info in the mobile data settings, which she provided us. That's when we realised that it is a very American / Apple thing because the US business model of mobile phone and carriers are very different from India. In the US, most mobile phones are sold through the carriers and Apple and its competitors have to work with them closely. Whereas in India, consumers purchase their mobile phones independent of the carrier.
mihaaly 3y ago
Friendly remark. Recently the term "consumer-friendly" became the synomym of "we shove it down your throat whether you like it or not!". If you wish to communicate some real user-friendly feature better find some other phrase. Reading "consumer-friendly" statements of providers makes me turn away and never look back. See the above example. Hijacking the device we use for our daily operations, very important one with sensitive data, already in risk from multitude of origins, hijacking it remotely into some unknown channels along hidden organisational incentives is a very offensive and frightening move. The technology is not new and it is OPTIONAL for very long time. Shoving it down the throat is bad. Very bad. (I am pretty disappointed with the population of the world that accepts anything from service providers for mostly marginal or never missed gains, accepting the elimination of choice. Providers feel they can get away with anything and became increasingly hostile.)
- tengwar2 3y ago
  To amplify this: a recognised problem with GSM/GPRS was that although the mobile device authenticated itself to the network. This introduced MITM vulnerabilities. As a response, 3G brought in mutual authentication. Do these managed WiFi networks have mutual authentication? As far as I know, no.
  - seraphsf 3y ago
    Yes, WiFi offload uses the Hotspot 2.0 spec with mutual authentication (EAP-AKA or EAP-SIM typically). Both the phone and the WiFi network will mutually authenticate with the carrier’s Authentication Server.
- jsty 3y ago
  If the use case is as described (connecting to WiFi APs owned and controlled by the network in deadspots / hotspots - e.g. stadiums and large buildings - and not end-user APs in homes), it's not clear to me that this poses any significant threat above and beyond connecting to the same operator's cell towers. If you don't trust them to run a WiFi network, probably shouldn't trust their cell network either. Having phones automatically and uncontrollably route via random 3rd party APs is a bad decision, but I didn't read GP as advocating for this.
cleanchit 3y ago
Why don't the stadiums just setup an open wifi network? (no password)
- JohnFen 3y ago
  Probably because the stadiums don't want to incur the expense of doing so. That scale of setup wouldn't exactly be cheap.
- karlshea 3y ago
  Some do. Allianz Field in St Paul has an open guest network, then you “sign in” with your email like you would at a coffee shop. It works great, super speedy. Definitely better than the cell network during a game.
JohnFen 3y ago
> (Also these WiFi offload networks are secure; you can’t spoof them) How do we know this? What's the security mechanism?
- seraphsf 3y ago
  Hotspot 2.0, a.k.a. Passpoint. Within that standard, the phones, WiFi networks, and carriers are all using EAP-AKA or EAP-SIM authentication.

sholladay 3y ago

Confirmed. I’m on one of the major carriers and after multiple hours, auto-join is still disabled after I turned it off. Though, I haven’t tried rebooting.

hk1337 3y ago
I’m in the same boat as you. It’s been off for almost 24 hours and I rebooted my device. I’m not using an eSIM like OP maybe that’s the difference, I don’t think so. I wonder if those with the problem were to restart or reset their device, if they would still have the problem?

divan 3y ago

Thanks for explanation. > they’ve disabled the user’s ability to turn off “auto-join” on iOS How (and why) is it even possible for carriers?

seraphsf 3y ago
Frankly, I don’t know. This thread is the first I’ve heard of it. Carriers ask phone makers for config changes all the time. It’s possible this is a new capability that was requested by certain carriers. To be fair, it’s also possible that the OP and I are misinterpreting what’s going on. For instance, iOS syncs your preferences across devices. Perhaps there’s some bug that’s causing the wrong setting to propagate back to this person’s phone because their iPads, etc are still set to allow “auto join”.
- stacktrust 3y ago
  > iOS syncs your preferences across devices. This theory could be tested by signing out of iCloud before changing "auto-join".
webmobdev 3y ago
> How (and why) is it even possible for carriers? This happened in India. So one day mobile data was quite slow on my non-Apple phone. I asked my friend to enable hotspot on his iPhone. We were stumped when we couldn't find the "Personal Hotspot" option at all in ios settings. Called Apple support who informed us that Hotspot option is only available if the carrier enables it. They asked us to contact the carrier. We were outraged and thought the carriers in India had suddenly decided to charge us extra for this option. Or maybe just for iPhone users. (In india, no carrier charges us extra for this option - and that is how it should be right? We are already paying more according to the bandwidth (3g/4g/5g speeds) and they also already limit how much data we can download. Imagine being charged extra for the "privilege" of sharing your data and consuming it faster!). We were prepared to yell at the carrier if they wanted more money from us for this but their customer support explained to us that this is a common complain they have with Apple iPhones, and all we needed to do was add some more info in the mobile data settings, which she provided us. That's when we realised that it is a very American / Apple thing because the US business model of mobile phone and carriers are very different from India. In the US, most mobile phones are sold through the carriers and Apple and its competitors have to work with them closely. Whereas in India, consumers purchase their mobile phones independent of the carrier.

mihaaly 3y ago

Friendly remark. Recently the term "consumer-friendly" became the synomym of "we shove it down your throat whether you like it or not!". If you wish to communicate some real user-friendly feature better find some other phrase. Reading "consumer-friendly" statements of providers makes me turn away and never look back. See the above example. Hijacking the device we use for our daily operations, very important one with sensitive data, already in risk from multitude of origins, hijacking it remotely into some unknown channels along hidden organisational incentives is a very offensive and frightening move. The technology is not new and it is OPTIONAL for very long time. Shoving it down the throat is bad. Very bad. (I am pretty disappointed with the population of the world that accepts anything from service providers for mostly marginal or never missed gains, accepting the elimination of choice. Providers feel they can get away with anything and became increasingly hostile.)

tengwar2 3y ago
To amplify this: a recognised problem with GSM/GPRS was that although the mobile device authenticated itself to the network. This introduced MITM vulnerabilities. As a response, 3G brought in mutual authentication. Do these managed WiFi networks have mutual authentication? As far as I know, no.
- seraphsf 3y ago
  Yes, WiFi offload uses the Hotspot 2.0 spec with mutual authentication (EAP-AKA or EAP-SIM typically). Both the phone and the WiFi network will mutually authenticate with the carrier’s Authentication Server.
jsty 3y ago
If the use case is as described (connecting to WiFi APs owned and controlled by the network in deadspots / hotspots - e.g. stadiums and large buildings - and not end-user APs in homes), it's not clear to me that this poses any significant threat above and beyond connecting to the same operator's cell towers. If you don't trust them to run a WiFi network, probably shouldn't trust their cell network either. Having phones automatically and uncontrollably route via random 3rd party APs is a bad decision, but I didn't read GP as advocating for this.

cleanchit 3y ago

Why don't the stadiums just setup an open wifi network? (no password)

JohnFen 3y ago
Probably because the stadiums don't want to incur the expense of doing so. That scale of setup wouldn't exactly be cheap.
karlshea 3y ago
Some do. Allianz Field in St Paul has an open guest network, then you “sign in” with your email like you would at a coffee shop. It works great, super speedy. Definitely better than the cell network during a game.

JohnFen 3y ago

> (Also these WiFi offload networks are secure; you can’t spoof them) How do we know this? What's the security mechanism?

seraphsf 3y ago
Hotspot 2.0, a.k.a. Passpoint. Within that standard, the phones, WiFi networks, and carriers are all using EAP-AKA or EAP-SIM authentication.