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How AT&T Recognizes Unauthorized Tethering from Jailbroken iPhones

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31–40 of 46 posts

Re: How AT&T Recognizes Unauthorized Tethering from Jailbroken iPhones

#31

They'll find other ways i.e. looking at the UserAgent in any unsecured HTTP request would signal tethering

Ah yes because it's impossible to spoof your user agent string be it with a 3rd party web browser on the iPhone or your desktop browser to match the iOS one.

sure but many websites use the useragent to alter the presentation for the device...this would diminish the experience for the lay user when tethering

Re: How AT&T Recognizes Unauthorized Tethering from Jailbroken iPhones

#32

They'll find other ways i.e. looking at the UserAgent in any unsecured HTTP request would signal tethering

Not really. You could always write a browser app for iOS or Android that uses Firefox or Chrome's user agent to have servers return the full desktop version.

If I was AT&T looking for unauthorized tethering folk, I'd focus on the people that are using > 2 GB a month + other various heuristics. Something deff smells funny if someone is using substantial bandwidth and much of the traffic is with a UserAgent like Firefox or Chrome

Re: How AT&T Recognizes Unauthorized Tethering from Jailbroken iPhones

#33
post #28
post #4

Earlier quoted context omitted.

Jailbreaking was given a temporary exemption from the DMCA. That doesn't mean it's necessarily legal, nor does it mean that it doesn't violate the terms of the contract with your carrier.

Doesn't that explicitly mean it's legal? At least for the time of the exemption.

No, it just means that it doesn't violate one part of one law: the anticircumvention provision of the DMCA.

And the exemption only applies if "circumvention is accomplished for the sole purpose of enabling interoperability of such [software] applications, when they have been lawfully obtained..." One could argue that skirting carrier rules on tethering is different from enabling interoperability.

Further, it has no bearing on any contract you may have with your carrier.

Re: How AT&T Recognizes Unauthorized Tethering from Jailbroken iPhones

#34
post #17

Note: TetherMe (native tethering on jailbroken iPhones) sends all tethered data through the same APN as mobile data by default so users won't fall foul of the APN detection method mentioned here. Of course that wouldn't stop AT&T & Co sniffing browser strings of high data users, but that's a more complicated system to implement.

Or just assume that high data users are all tethering.

Re: How AT&T Recognizes Unauthorized Tethering from Jailbroken iPhones

#35
post #18

Earlier quoted context omitted.

> The (slightly) more interesting legal question might be whether AT&T could ask a prosecutor to bring criminal charges. My uninformed guess is they could, based on something like "theft of services." If I charged $20 a month for you to come fill up a one-gallon bucket any time you wanted from my well, and instead of a bucket you filled up a tanker truck, it would be theft plain and simple, because you'd knowingly be…

The problem is that they sold you "all the water you could carry" and then reneged when you pulled in with your truck (with the bucket they gave you duct-taped to the inlet with a hole in punched in the bottom). Its a case of "wait! I didn't really mean all ". Its the classic fat man at the buffet problem.

>The problem is that they sold you "all the water you could carry" and then reneged when you pulled in with your truck (with the bucket they gave you duct-taped to the inlet with a hole in punched in the bottom).

What they sold you is in the contract, which specifies non-tethered data access. To continue your water analogy, they sold you all the water you could carry in that bucket, and you signed a contract saying you wouldn't try to connect the bucket to anything else.

This is really straightforward contract law. If you want to do something, don't sign a contract promising you won't do it.

Re: How AT&T Recognizes Unauthorized Tethering from Jailbroken iPhones

#36
post #16
post #5

Does anyone know if tethering can be detected on Android phones? I'm curious what other provides do to try to detect tethering on Android phones.

I wrote a non-root tethering app, so I might have a bit of tunnel vision. First, any good tethering app should be immune to a simple TTL check. The most likely culprits are instead application traffic patterns. The following immediately come to mind: - Browser user agents - Automatic status checks under both OS X and Windows - Application behavior: * Netflix and Hulu on Android isn't supposed to happen. * Browsers li…

> First, any good tethering app should be immune to a simple TTL check.

If the phone sets its TTL to 255, what can you do?

Re: How AT&T Recognizes Unauthorized Tethering from Jailbroken iPhones

#37
post #19
post #15

Earlier quoted context omitted.

Tethering isn't a service though. The service is the data transfer. Tethering is a feature of the phone (which you own, especially if out of contract). Here's a metaphor: Imagine if the water company charged you per gallon for water you used, but then added an additional charge for having a shower. Since you own plumbing fixtures to which the shower connects, and pay for every gallon, we would consider it unfair for…

However, the water company will most definitely come looking for you if you start selling water to the neighboring town that has higher water prices, since then you are profiting from your subsidized water. The real problem is that somehow the wireless companies, unlike residential ISPs, have gotten away with not being labeled as pure data transfer companies. It should be none of their business what data you send, bu…

The dumb pipe argument has been around for a couple years now. These companies (cable, satellite, telecom) absolutely do not want to become utilities. It limits their control over their product, and cuts off several high-yield revenue streams.

If they were regulated like a utility (water or electricity, for instance), you would see any and all arbitrary surcharges disappear, and these happen to be the biggest cash cows for these companies.

Re: How AT&T Recognizes Unauthorized Tethering from Jailbroken iPhones

#38

A couple of years back, federal regulators (thanks to the efforts of EFF) declared that jailbreaking an IPhone is not illegal. Since then, Apple has stopped threatening users with jailbroken IPhones, and also, finding and patching new vulnerabilities that allow jailbreaking has become a moot point. In the same vein, has there ever been a verdict on the legality of unofficial (MyWi-like) tethering?

It was actually (according to the EFF) 1) just last year, 2) the Copyright Office, 3) jailbreaking specifically for the purpose of interoperability with lawfully obtained software or for connecting to different providers with the authorization of said providers, 4) specifically w.r.t. the DMCA rulemaking process. https://www.eff.org/press/archives/2010/07/26

Re: How AT&T Recognizes Unauthorized Tethering from Jailbroken iPhones

#39
post #36
post #16

Earlier quoted context omitted.

I wrote a non-root tethering app, so I might have a bit of tunnel vision. First, any good tethering app should be immune to a simple TTL check. The most likely culprits are instead application traffic patterns. The following immediately come to mind: - Browser user agents - Automatic status checks under both OS X and Windows - Application behavior: * Netflix and Hulu on Android isn't supposed to happen. * Browsers li…

> First, any good tethering app should be immune to a simple TTL check. If the phone sets its TTL to 255, what can you do?

The goal is not to forward packets blindly like a NAT. You emulate the NAT's behavior by running a TCP state machine in user space and converting packets to regular Android SDK calls. This is what all of the non-root tethering apps likely do, because raw socket access is not allowed.

Re: How AT&T Recognizes Unauthorized Tethering from Jailbroken iPhones

#40
post #26
post #15

Earlier quoted context omitted.

Tethering isn't a service though. The service is the data transfer. Tethering is a feature of the phone (which you own, especially if out of contract). Here's a metaphor: Imagine if the water company charged you per gallon for water you used, but then added an additional charge for having a shower. Since you own plumbing fixtures to which the shower connects, and pay for every gallon, we would consider it unfair for…

You pay for the data you transfer. Tethering is simply an "unauthorized" (by the vendor) use of that data Wait, does anyone charge a per-kilobyte data charge? I thought most plans either had unlimited data or some large cap.

In the UK, most providers charge per-kilobyte. For example, I'm on a contract that gives me 1GB per month. Anything beyond that and I pay extra. It annoys me greatly that tethering isn't included in that (and costs a lot more), whether or not I use the 1GB that I've already paid for.
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