How AT&T Recognizes Unauthorized Tethering from Jailbroken iPhones

Last week at a conference, I spoke briefly to an engineer from one of the large two US telcos on this issue. He indicated they utilized a variety of methods, including utilized fingerprinting of the IP/TCP headers, and protocol analysis to help identify traffic. Specifically, I heard TTL mentioned, as well. He might be a user here.<p>There are more knowledgeable people than you working on the issue. That said, I haven't gotten an evil text from using PDAnet, yet. Then again, I don't tether that much and when I do it's not a lot of data.

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.<p>Of course that wouldn't stop AT&#38;T &#38; Co sniffing browser strings of high data users, but that's a more complicated system to implement.

I'd like to see a proper source of this (other than Android Police / iPhone Download Blog). I have used MyWi without having any special settings for tethering (my provider doesn't supply those), and it worked just fine; it would be a bit silly to go through the trouble of setting up a hotspot and making sure you're actively routing the data to the 'wrong' APN.<p>(Note that iPhone Download Blog is the one calling MyWi by name)<p>Also, if this is the case, wouldn't it be easier for AT&#38;T to just disable the tethering APN for you if you don't have the tethering option? That would seem to be much more effective.

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.<p>In the same vein, has there ever been a verdict on the legality of unofficial (MyWi-like) tethering?

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 tested my Verizon HTC Thunderbolt 4G's download speeds today. I got over 7 megabits per second down. It also got 4 megabits up!

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

I heard they checked for varying TTL values?

anyone actually knows what the old unlimited contract says about this?