How AT&T Recognizes Unauthorized Tethering from Jailbroken iPhones

By , May 8, 2011

In case you didn’t know, AT&T has started cracking down on unauthorized tethering, specifically for jailbroken iPhones on a grandfathered unlimited data plan.

If you’ve gotten AT&T’s “text of death” relating to your tethering usage, you’re probably utilizing free tethering through jailbreak apps like MyWi. Understandably, AT&T doesn’t want its users to have a free broadband connection through tethering hacks, and the carrier has started moving users over to its DataPro plan for $45 a month.

So, how is AT&T targeting unauthorized tethering on its network?

Android Police,

“Jailbroken iPhones typically use the same tethering technique as a standard iPhone, the one that’s already present in iOS. This method exposes tethering activity quite readily, because the iPhone, when in tethering mode, sends traffic through an alternate APN (AT&T access point/router) for the express purpose of identifying the traffic as tethered data. This makes it extremely easy for AT&T to identify whether or not an iOS device is utilizing tethering, and just how much of their data is consumed via tethering.

Some tethering applications for iOS make use of alternative methods and route tethered traffic through the phone’s normal data APN, but by and large, most jailbreakers stick with the stock application because it’s easy to use and doesn’t require any complicated setup. In fact, many iPhone users jailbreak for the sole purpose of avoiding AT&T’s tethering fees (for why, see next section). These are the people AT&T’s is going after.”

Because MyWi, the most popular tethering alternative for jailbreakers, uses the same APN as the standard tethering system for iOS, AT&T can see a jailbroken iPhone’s tethering activity very easily. AT&T has been contacting its list of unauthorized tethering users in waves, and there are no signs that the warnings from AT&T will stop anytime soon.

The people getting targeted by AT&T are obviously those with a grandfathered unlimited data plan. If you’re fortunate enough to still have an unlimited data for your iPhone, you can tether till your heart’s content through methods like MyWi and never have to worry about going over on your bill. AT&T doesn’t like that jailbreakers are able circumvent their $45 system for tethering.

There are other options for tethering in Cydia. PdaNet is an alternative to MyWi that has a new option to “hide” your tethering usage, assumedly redirecting you to the regular APN that the iPhone uses for data. If PdaNet does indeed mask your data from being sent through AT&T’s tethering APN, then AT&T should have no way of distinguishing unauthorized tethering data from regular data.

TetherMe is another popular tethering solution for jailbreakers that hasn’t gotten much attention in this whole AT&T debacle. From what we’re hearing, TetherMe users are reporting that they haven’t gotten contacted from AT&T about any sort of unauthorized tethering. However, this doesn’t mean that TetherMe users will not be contacted by AT&T soon.

As of right now, it seems that the updated version of PdaNet is your best bet for safe, free tethering on a jailbroken iPhone. Although AT&T does mainly use APNs to distinguish different types of data, your carrier could also be able to sniff data packets to see different types of traffic.

What’s been your experience with this tethering issue on AT&T? Have you been contacted by AT&T about unauthorized tethering? What method do you use for tethering on your jailbroken iPhone? Share your thoughts and stories with us below!

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  • Anonymous

    I never got the text or email of death about my data usage and I used between 50GB to 90GB
    I posted my graph here in this site: dgray337.blogspot. com
    Riding My Unlimited Till The End!!!

    • Tom Mangum

      AT&T is really pissing me off. Tethering was included in my unlimited plan but it wasn’t written in the contract I had with Cingular when I got the data plan on the Blackberry 6800 I bought the day it came out full retail because I wanted to keep my Suncom UN-Plan. Yes, I still have a Suncom UN-Plan…been out of contract like 7 or 8 years. Tethering was not common back then but it was a fucntion the phone could do being I paid to have a BES Blackberry Unlimited Plan. Enterprise Server connection and tethering. I changed to a WM device with BB Connect. Then to Android. Root, Custom ROM & use hotspot I”m good for many months till i go over 2gigs and get a “no tether” txt and letter.
      All these carriers want is to get more money out of you. Like all the bloat apps they put on the phone… Why you want to use the carrier navigation app when its free with google maps. It’s why carriers block saving your contacts to Gmail because they want you to use their contact backup service or some crap.
      Now the latest is if you use over 3gb on an unlimited plan you get throttled.

  • Tom Mangum

    AT&T is really pissing me off. Tethering was included in my unlimited plan but it wasn’t written in the contract I had with Cingular when I got the data plan on the Blackberry 6800 I bought the day it came out full retail because I wanted to keep my Suncom UN-Plan. Yes, I still have a Suncom UN-Plan…been out of contract like 7 or 8 years. Tethering was not common back then but it was a fucntion the phone could do being I paid to have a BES Blackberry Unlimited Plan. Enterprise Server connection and tethering. I changed to a WM device with BB Connect. Then to Android. Root, Custom ROM & use hotspot I”m good for many months till i go over 2gigs and get a no tether txt and letter.
    All these carriers want is to get more money out of you. Like all the bloat apps they put on the phone… Why you want to use the carrier navigation app when its free with google maps. It’s why carriers block saving your contacts to Gmail because they want you to use their contact backup service or some crap.
    Now the latest is if you use over 3gb on an unlimited plan you get throttled.

  • http://www.facebook.com/gotsteam Fred Gotsteam

    I don’t have a smart phone and I received the text and the letter on the same day! I use my phones Bluetooth feature to connect to my netbook and simply log onto the network using the bluetooth dial-up network service. I do have the unlimited data plan for my basic phone so how do they know? Amazingly I’ve never used more than 4 gigs of data a month as I keep tabs on it. I am wondering if they actually know I used to tether my netbook or if they just sent out the letters to everyone with an unlimited data plan. By the way, I called AT&T and told them I don’t have a smart phone and they removed the additional tethering fee from my bill… At least thats what they told me. We’ll see.

  • Monica Jae

    i use PDAnet for thethering…It DEFINITELY hides my usage. I know this because once I forgot to activate the “Hide Usage” control and AT&T sent me a notice that they had a tethering plan if I wanted to do that. After that I started hiding usage and NEVER had a problem. I’m on the 3gig plan and sometimes I download really large files to my PC using PDAnet and never exceeded the allotted amount! The only complaint i have is that it never gets the 3G speeds. It only seems to get the 802.11g speed–54Mbs. I wish they’d update to reflect LTE since i’m gonna get the 5S–and when i’ll be able to jailbreak it…kinda nervous about it tho…