AT&T detects tethering - How?

Discussion in 'iPhone' started by Rascol, May 5, 2011.

  1. Rascol macrumors newbie


    May 5, 2011
    I spent quite a bit of time trying to figure out how they do it. Then I followed the Corporate trail as to who's software or services they would be using to do this... and lo and behold - I found the answer.

    The have picked up Ciscos Openet - Orange France - and using FusionWorks DPI to detect tethering. I don't know exactly how this works - so if you get this post - there is your answer. How do you conceal tethering through Deep Packet Inspection? And is this even legal for AT&T to do because of some of the Privacy acts from 1988 to now.

    The worst part of this is that after talking with AT&T - I have the $30.00 unlimited data plan grandfathered into my contract. I have had the same plan for 3 years now - and AT&T claims through their contract they can just add changes and I must adhere to them. Not as if I signed a contract stating I agree with the new tethering policies. I didn't. They just enforce. And you can't just cancel the contract without paying the termination fee. They waited til after I renewed to hit me with the email and texts. Dirty in my book! The kicker is I don't use that much data at all. I rarely tether and only do so when there is no access around and I must service a client - Then I usually use it for LogMeIn or email. My kids use the iPhone for Netflix and they use a ton of data. As pissed as I was with AT&T - I let them know if they are trying to cut down on usage - I wasn't going to comply.... I was going to run the crap out of Netflix and quadriple my usage - just to prove a point - I can be an ass too. They didn't like my statement to much!

    So - anyone who can figure out how to hide tethering through DPI is going to be a hero.
  2. mltaylor macrumors regular

    Jan 6, 2011
    Some how...some way...someone will figure out how to hide it. Only a matter of time.
  3. Dr Kevorkian94 macrumors 68020

    Jun 9, 2009
    SI, NY
    Well from what I read on wikiapidia DPI can check the packets for a certain criteria, the criteria being the packets that are for the iPhone. Another thread came up with the idea that the packets TTL is different for each devise so if that is what is being checked then the the TTL can be modified if u have a jail broken iPhone. So if we can find out what is being checked then it could esily be masked or changed to fit the criteria. Here is the thread:
  4. MaxBurn macrumors 65816


    Nov 25, 2010
    Lots of ideas but no one knows really. The methods for finding out aren't really good at all now either!
  5. Applejuiced macrumors Westmere


    Apr 16, 2008
    At the iPhone hacks section.
    No one knows but also the process they're using has many flaws.
    They send many of those texts and emails to people who dont unofficially tether and are not even JB.
    Something doesnt make sense.
  6. b166er macrumors 68020


    Apr 17, 2010
    I think a lot of those "you're tethering" text messages are a combo of scare tactic and marketing.

    You send out a million of those texts, there is a good chance a lot of people who get it ARE tethering unofficially and will just change their data plan because they don't know any better.

    I'm sure ATT targets the high data users, but I don't think they have an exact method to know for sure that you are or are not tethering. When I tether I STILL don't go over 3gb a month because I only tether for a few minutes (like until the wifi gets fixed, etc).

    Some people don't tether at all, aren't jail-broken, and their data usage is tens of gigs a month. And a lot of them have gotten those text messages even though they are not doing anything wrong.

    In short, I think ATT regrets ever offering us unlimited data and they are trying to get people to switch.
  7. Daveoc64 macrumors 601

    Jan 16, 2008
    Bristol, UK
    If that's really how they feel, they could easily just phase out Unlimited Plans.
  8. ewplayer3 macrumors newbie

    May 4, 2011
    I'm just going to go straight to the end of the OPs post. As far as the contract you signed... well, the last one I signed with ATT nearly 3 years ago said... well, I can't qoute it verbatim, but the legal gist of it was that AT&T has the right to changes the terms of the contract you signed, dynamically, with no need to notify its users about doing so.

    They've also got a nice clause that says you can't sue them if you are under contract with them. That likely wouldn't hold up in court, but still amusing.

    I can't explain how these companies are able to get away with half of what they do, but they do it somehow. Sit down sometime and read your contract. You'll likely have to have surgery to reattach your jaw once you've finished.
  9. DeaconGraves macrumors 65816


    Apr 25, 2007
    Dallas, TX

    Apple probably wishes they could get rid of unlimited plans, but would much rather have those grandfathered plans than have all those people jump ship to another carrier.

    Getting rid of unlimited plans would have two consequences. 1) those under contract would likely have to be given the ability to "opt out" due to a material change in the contract. 2) those out of contract could go elsewhere with no consequence.

    While the technolgy behind "detecting tethering" isn't perfect yet, AT&T would rather boot those few off the network as opposed to all unlimited plans.
  10. chakraj macrumors 65816


    Feb 6, 2008
    So Cal
    You can not put in a contract that you can change the contract at any time. That would be an easy contract to get out of.

    Everyone needs to realize a contract is between two people (or entities), they can change it and so can YOU. When they tell you they are going to do ....... that is just an offer. There are four answers to any offer.

    1. You agree (don’t do it)
    2. A non response is a YES (remember that for life)
    3. You can say NO, then there is a dispute and it will go to a third party to deliberate. (Don’t do it)
    4. Or you can conditionally agree (on whatever condition you want)

    A conditional agreement has the effect of accepting the offer , but changing it to whatever you have conditioned.

    Lets say "I conditionally agree you can change my plan, on the condition that you show me the origional contract signed by both parties that requires me to do so" and on and on......
  11. goMac macrumors 604

    Apr 15, 2004
    Doesn't matter how rarely you do it. You broke your contract, and in your contract ATT reserves the right to charge you for tethering if you tether.

    I don't like it, and I'm sure you don't, but it's what you agreed to. There isn't anything unfair about this.

    I would also note that if ATT changes your contract, you do not have to agree to the new contract. At that point you can actually leave the contract without penalty.
  12. b166er macrumors 68020


    Apr 17, 2010
    They ARE phasing out unlimited plans. This is just one link in the chain. Us who have "unlimited" plans are being asked to keep it under a preset limit, or be forced to switch to a limited plan.

    Wait until LTE/4G. If you think you're getting an unlimited LTE plan with ATT, don't hold your breathe. I hope I'm wrong about that, but I doubt we'll get them. My money is on all of us being forced to switch to a limited plan to get the new service.
  13. Rascol thread starter macrumors newbie


    May 5, 2011
    Broke My Contract?

    GoMac - I signed up for my cell service when AT&T offered the unlimited plan and no tethering what-so-ever. And so - my data consumption is very low EXCEPT for the Netflix vids my kids watch. As far as tethering - I rarely do. When I do - it's for a couple of minutes - usually to modify a server setting.

    Fast forward now - they tell me they switched the agreement I signed 3 years ago to include a new policy on tethering which I must adhere to.... really - that is about ridiculous. And now they reserve the right to cancel my existing data plan and charge me more? I found out from a lawyer friend of mine that I can easily get out of my contract if they do that - regardless of their claims. In Florida anyways....

    So - I am onto a couple of ways to spoof the DPI - but for now - I agree with a previous post - they are just barking loud.

    Answer one question though... Why is it OK for them to limit my unlimited data plan??? It's UNLIMITED! So who cares if I tether.... it's UNLIMITED! Now all of a sudden, it's LIMITED when it's UNLIMITED???

    That my friends is the joke of the day!

    I also plan on quadrupling my data usage by running Netflix all day long.... just to prove a point! I won't be tethering either!
  14. nastebu macrumors 6502

    May 5, 2008
    This has been asked and answered many times. Your contract isn't for unlimited data on any device. It's for unlimited data on your phone. Tethering is a use that is not included in that contract. It's like me saying I pay my rent in my apartment, so that should entitle me to stay free at the Hilton.

    You have the right to do that, but why would you? You're just wasting electricity and bandwith and making the world a slightly meaner and less generous place. And AT&T doesn't care. You would probably be hurting Netflix more than AT&T.
  15. yg17 macrumors G5


    Aug 1, 2004
    St. Louis, MO
    It's for unlimited data on your phone. You can't go into an all-you-can-eat buffet and start loading up Tupperware containers to take food home for your family even though you only paid for yourself.
  16. MaxBurn macrumors 65816


    Nov 25, 2010
    That's actually a really good example, I like it.
  17. Goldinboy17 macrumors 65816


    Jun 21, 2010
    San Francisco, Ca
    I tether just about every single freakin' day. No text or warning from AT&T. Somebody's BS'ing.
  18. ap3604 macrumors 68000

    Jan 11, 2011
    tetherme? miwi? or pdanet?
  19. Goldinboy17 macrumors 65816


    Jun 21, 2010
    San Francisco, Ca
    MiWi. I tether very often but I'm really not a very heavy user. Maybe that's why?
  20. 0815 macrumors 68000


    Jul 9, 2010
    here and there but not over there
    My guess is that it is mostly a blind guess on their side based on data usage (or patterns of usage) .... but I could also imagine that they look (through some automated process) at the http headers and get suspicious if IE8 shows app as user-agent from your iPhone data plan ....

    finally a sensible comparison - paying for unlimited food (=data) for one person (=phone) does not allow you to feed all persons (=computers) in your household. .... Best analogy, thank you, I have to remember that one - I hope I may quote this whenever needed.
  21. Wicked1 macrumors 68040


    Apr 13, 2009
    New Jersey
    Only a matter of time before they are start offering a tier level pricing.

    AT&T was crushed under the iPhone, Verzion even stated it is only going to be a limited time under the $29.99 plan.

    I do not think Sprint and T-Mobile have to worry as they do not have nearly the amount of users and Data going thru their network.

    I have unlimited, grandfathered over, even at my highest usage without much WiFi, I just use slightly over 1.2GB.

    To those who are sucking up more than 5 GB a month, they should pay more, unless AT&T kicks me off Unlimited or offers me something in between 250MB and 2 GB, I will just stay where I am. I do not tether anyway because in order to do this, I would have to go with the 2GB package and tethering with another 2GB for 4 GB costing me $45.00 per month, just not worth it at all.
  22. drummr macrumors regular

    Feb 17, 2011
    Why is that? Is it not an UNLIMITED data plan? Meaning no limit. I used 17gb last month.
  23. Goldinboy17 macrumors 65816


    Jun 21, 2010
    San Francisco, Ca
    You used 17GB on your phone in one month? Now you didn't cheat by tethering did you?
  24. Rascol thread starter macrumors newbie


    May 5, 2011
    Finally answers....

    “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.”

    So it appears, apps that use the special data APN get noticed by AT&T’s systems, hence the strong-arm tactics. Popular jailbreak app MyWi works just as described by AndroidPolice – using the tethering APN. What we need is an app that uses the same APN as your iPhone does for its own data. According to the iPhoneDownloadBlog, that app is PdaNet.
  25. Stealthipad macrumors 68040


    Apr 30, 2010
    Unlimited Data plan and tethering are two different thing. Do not see how some could think it is the same. So many wanting to get something for nothing!

    This is why we are in the mess we are now and near bankrupt!

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