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  • AT&T Cracking Down on MyWi Tethering?


    We've gotten a couple of tips today from users saying that they are receiving notices from AT&T regarding tethering. These users have been using MyWi for tethering, and are grandfathered into AT&T's old unlimited iPhone data plan.

    For one user, the notices began as a simple text message:
    "AT&T Free Msg: Did you know tethering your Smartphone to a computer requires a tethering plan? Pls call 888-860-6789 for details or visit att.com/dataplans."


    AT&T then followed up with this message via email:

    Dear [Customer],

    We've noticed your service plan may need updating.

    Many AT&T customers use their smartphones as a broadband connection for other devices, like laptops, netbooks or other smartphones– a practice commonly known as tethering. Tethering can be an efficient way for our customers to enjoy the benefits of AT&T's mobile broadband network and use more than one device to stay in touch with important people and information. To take advantage of this feature, we require that in addition to a data plan, you also have a tethering plan.

    Our records show that you use this capability, but are not subscribed to our tethering plan.

    If you would like to continue tethering, please log into
    your account online at Cell Phones and Cell Phone Plans - Wireless from AT&T, or call us
    at 1-888-860-6789 Monday - Friday, 7 a.m. - 9 p.m. CST
    or Saturday, 8 a.m. - 7 p.m. CST, by March 27, 2011
    to sign up for DataPro 4GB for Smartphone Tethering.
    Here are details on the plan:

    DataPro 4GB for Smartphone Tethering
    • $45 per month
    (this gives you 4GB in total, combining both your smartphone data plan for $25 and the tethering feature, $20)
    • $10 per each additional GB thereafter, added automatically as needed
    • Mobile Hotspot capabilities are included for compatible Smartphones

    If we don't hear from you, we'll plan to automatically enroll you into DataPro 4GB afterMarch 27, 2011. The new plan – whether you sign up on your own or we automatically enroll you – will replace your current smartphone data plan, including if you are on an unlimited data plan.

    If you discontinue tethering, no changes to your current plan will be required.

    It's easy to track your usage throughout the month so there are no bill surprises. For example, we send you free text messages when you reach 65, 90, and 100 percent of your plan's threshold. If you would like to monitor your account more closely, go towww.att.com/dataplans to learn about other ways to track your data usage.

    As a reminder, our smartphone data plans also include unlimited usage of Wi-Fi at no additional charge. AT&T smartphone customers can use Wi-Fi at home or on-the-go at any one of our more than 23,000 U.S. hotspots already included in your data plan.

    Thank you for bringing your account up to date. We appreciate the opportunity to continue to serve your mobile broadband needs.

    Sincerely,

    AT&T
    This is the first we've heard about users receiving messages regarding MyWi tethering from AT&T. One speculation as to how AT&T may know about tethering is the iOS 4.3 update, which allows the iPhone to be used a personal hotspot. It's possible that AT&T can now track data usage specifically to the device that's being tethered, regardless of whether its done through the personal hotspot feature in 4.3 or via MyWi.

    We'll keep you posted if we hear anything more on this issue. Thank you very much to the readers who sent this in to our tips email!

    UPDATE: Based on user comments that some users are getting the message that don't tether at all, it looks like AT&T is targeting users who have high data usage. As it turns out, MyWi shows up as 0 tether bytes.

    This article was originally published in forum thread: AT&T Cracking Down on MyWi Tethering? started by Matt Savoca View original post
    Comments 1466 Comments
    1. szr's Avatar
      szr -
      Quote Originally Posted by confucious View Post
      Speed or amount of data has nothing to do with it, CDMA was never designed for tethering and tethering rally is awful from a network point of view.

      Just because it doesn't work doesn't mean you won't make them do it in the USA. Her in the UK we would rather have the choice to pay less, I'd rather pay £10/month for my phone and be restricted to only 1Gb data 100 texts and 250 mins as that is plenty for me but I guess you do things differently over there.
      Quote Originally Posted by confucious View Post
      Read my previous posts. Tethering blocks channels. Not sure what more I can say really.
      I believe what makes the difference in how tethering impacts a cellular network is how it's activated. On most devices, like the iPhone and many Android phones that I've seen, tether traffic is sent through a separate APN than what the phone normally uses for DATA, Visual Voice Mail, SMS/MMS, et al. I've noticed some time ago that if you reconfigure your settings so that tethering also goes through the phone's primary APN (which can be accomplished by modifying the type-mask of the appropriate APNs.) Once that is done, the carrier (tested on AT&T mainly) appears to have no way, aside from maybe inspecting packets closely (although this become less and less viable as more and more apps have proliferated that utilize or mimic many former computer-only network services,) of discerning tethering and non-tethering data packets. In such a case the phone is just functioning as a software NAT/router as well as either a USB network adapter or wireless access point.

      Quote Originally Posted by csglinux View Post
      If I send data through an encrypted VPN tunnel, how will you (or any carrier) know that data was actually tethered. You won't. Therefore there's no way that data could possibly be treated any differently than if it had originated on the phone itself.
      It can be detected when it's going through a separate APN, which is the case on many carriers like AT&T. I can't really speak to how Verizon and Sprint but I believe it work similarly. Going through a separate APN is also how they are able to have a separate usage section just for tethering. If you configure your cellular settings so that tethering goes through the phone's primary APN, then you'll notice the tethering section on your device's usage page no longer increments.
    1. csglinux's Avatar
      csglinux -
      Quote Originally Posted by szr View Post
      It can be detected when it's going through a separate APN, which is the case on many carriers like AT&T. I can't really speak to how Verizon and Sprint but I believe it work similarly. Going through a separate APN is also how they are able to have a separate usage section just for tethering. If you configure your cellular settings so that tethering goes through the phone's primary APN, then you'll notice the tethering section on your device's usage page no longer increments.
      That's correct. There have been carrier profile hacks in the past that enabled the tether APN, but all the popular tethering packages available via Cydia these days (MyWi, PDANet, TetherMe) use the phone's APN. DPI could still figure out what's really going on with those routed packets. But now imagine all traffic is sent through a VPN tunnel via the phone's APN. All the carrier would see is encrypted data going to/from the VPN host/client. There'd be no way of knowing what's in those packets and whether their final destination were on the phone or not. In this specific situation, I cannot see how tethering traffic could possibly be treated any differently (i.e., tie up more channels) than non-tethered data.
    1. confucious's Avatar
      confucious -
      The problem I was referring to has nothing to do with the APN, while they use different APNs now to better manage the traffic the problem was discovered on a single APN.
    1. szr's Avatar
      szr -
      Quote Originally Posted by confucious View Post
      The problem I was referring to has nothing to do with the APN, while they use different APNs now to better manage the traffic the problem was discovered on a single APN.
      I tend to agree with you that the problem that you describe has little to do with what APN is being used (I believe that's being used more as a means of tracking usage, as it no longer accumulates if you eliminate the usage of the secondary APN as I described before) but I really get the feeling, after rereading a lot of your posts and what you have linked to, that the problems you described have more to do with older systems and devices that conducted tethering in a different manner, where the carrier side was more involved, where as more modern devices like the iPhone and many Android based handsets have the tethering feature built-in, where the device is acting as a NAT router, sharing it's public address the same way a typical cable or DSL router would.

      If this is true, only inspecting each packet (DPA as you've noted before) would be able to possibly reveal that tethering is actually occurring (assuming no encrypted tunnels are being used and assuming the primary APN is being used.) Even, it's become increasing more difficult to make a conclusive assumption that one is tethering with the increase in apps (for for iOS and Android alike) that are able to utilize the same sort of online services as full-on computers. And if packets are being properly NAT'ed (again, just as a typical router would do), then even TTL wont be conclusive measuring stick, but that depends on how the packets themselves are being handled by the NAT software being used in the device.
    1. confucious's Avatar
      confucious -
      I hope you are right.
      My concerns are that UK providers still ban tethering. Even Three (apart from their top plan) if it was just the amount if data I don't believe they would.
      I could be wrong and am drawing conclusions based on very little evidence now but I have seen nothing to suggest things have changed.
    1. szr's Avatar
      szr -
      Quote Originally Posted by confucious View Post
      I hope you are right.
      My concerns are that UK providers still ban tethering. Even Three (apart from their top plan) if it was just the amount if data I don't believe they would.
      I could be wrong and am drawing conclusions based on very little evidence now but I have seen nothing to suggest things have changed.
      What seems to have changed is the handsets. Years before the iPhone, Android, and such came about, devices, especially in the day of the "PDA", afaik, didn't have the same sort of built in tethering capability and instead relied on either extra equipment (aka a "cellular modem") (or a device that contained such a modem) giving you two separate lines, which is like having two DSL or cable modems rather than sharing a single IP (a la your home router,) albeit I don't think that was actually referred to as "tethering." How ever the actual configuration was, though, I recall it always being billed as a separate line. I'm not sure if the iPhone and Android handsets were the first to perform actual NAT directly themselves, but what I can say is that it works quite differently than older devices.