O2, "We'll Disconnect Free iPhone Tetherers"

[jck1634]

Just read this article over at Techrader

They'll disconnect or charge people who they think are tethering for free. Still not sure how they would know other than an increase in usage.

"Internet rumours suggest that some customers have modified their iPhone to enable Internet Tethering without the purchase of the Internet Tethering Bolt On. Any use of this particular feature without the purchase of the Bolt on is specifically prohibited under our terms of service...

...Under those terms we reserve the right to charge customers making modem use of their iPhone or disconnect them."

You have been warned!

 

[bigscotal]

Just read this article over at Techrader

They'll disconnect or charge people who they think are tethering for free. Still not sure how they would know other than an increase in usage.

"Internet rumours suggest that some customers have modified their iPhone to enable Internet Tethering without the purchase of the Internet Tethering Bolt On. Any use of this particular feature without the purchase of the Bolt on is specifically prohibited under our terms of service...

...Under those terms we reserve the right to charge customers making modem use of their iPhone or disconnect them."

You have been warned!

What do they honestly expect, when their tethering bolt on is so ridiculously priced? Times are hard enough just now, and they want ~£15 to use data that most of us would argue should already be included as part of our contract already. I mean, WTF??

Bring the price down to something affordable (£5 p/m??) and I believe that most folk would just stump up and be done with it.

 

[Phil A.]

Still not sure how they would know other than an increase in usage.

Because the iPhone effectively acts as a NAT router when in tethering mode, it is technically possible to detect whether the TCP traffic has come straight from the phone - most simply by manipulation of the TTL (Time to Live) value in the packet: Whenever a TCP packet goes through a router, it's TTL value is reduced by one, but Apple could even have introduced a particular TTL value to identify tethered data.

So, for example, all traffic directly from iPhones coming into O2's gateways will probably have a TTL of 128. If it's from a tethered machine, the iPhone "router" will reduce that to 127 based on standard router behavior.

If Apple have been really sneaky, they could change it to something completely different to positively identify that your device is tethering to providers.

Don't forget that the first place any data on a mobile connection goes is through the equipment of your provider: They can find you out if they're so inclined...

 

[koollectablz]

Well if I'm disconnected does that mean it cancels my contract without me having to pay up for the rest of it?

Might do it just to enable me to get out of the contract without having to stump up.

Then I can just jailbreal, unlock and use a PAYG sim.

 

[Sebby]

I'm not condoning the tethering hack, but seriously, what do O2 expect? £15 for data that we're already paying for? That's ridiculous. And I wouldn't mind if they actually invested in their network, but they don't.

 

[Mess]

as long as its not used in excess that i dont see how they can have an issue with it. You pay for your data with your contract and pay enough for it. Why shouldnt we use the full potential of the phone we pay so much for.

 

[Padaung]

as long as its not used in excess that i dont see how they can have an issue with it. You pay for your data with your contract and pay enough for it. Why shouldnt we use the full potential of the phone we pay so much for.

Agreed, I'm not an iPhone user but I can sympathise with that. Why call it an unlimited data plan* if as soon as the phone is tethered the data becomes something other than data and needs to be charged extra for.


*fair usage terms and conditions apply (ie O2 don't want you to use too much unlimited** data and they don't want you to view it on a screen bigger than the one on an iPhone).

**I do understand the point of this as they (and the rest of us) don't want their networks being slowed down by bandwidth hoggers.

 

[sjdigital]

Don't forget that the first place any data on a mobile connection goes is through the equipment of your provider: They can find you out if they're so inclined...

Would using a VPN connection get round that problem?

 

[NATO]

*if* O2 have the means (and the will) to identify users who have bypassed the official tethering route, the main area of concern is how O2 react. I really don't see O2 disconnecting you since they would lose revenue, however I've seen other telcos charging their standard 'out of bundle' data prices, something like 19.6p per MB which wouldn't be cheap if you're downloading a gigabyte or more.

Over the years I've seen reports where people have connected their phones to their laptops and used it to download TV episodes etc, then got an absolutely ridiculous bill (£10k+) from their mobile phone company.

It's risky, you have to assume O2 can't easily find out because if they can then with this being such a widely publicised hack, they will act swiftly.

 

[thep33t]

Would using a VPN connection get round that problem?

No, it wouldn't do that. A VPN connection would encrypt the data being sent, but not touch the actual TCP overhead. In otherwords, apple couldn't read your data, but still can trace it in this fashion.




On another note, you all do realize that a mobile phone using the internet (which, by the way, is what is stated in your contract one way or another), uses SIGNIFICANTLY less bandwidth than a laptop. Your iPhone has one to two things connected to the internet at a time, while most laptops have many processes going, as well as the capability to just demolish the network. (Think P2P downloads).

If you are not happy with this fact, call ATT (or your provider), ask them to disable data, change your APN, and then you wont be paying for something you already were not paying for...

 

[Willis]

fun for while it lasted... GOD DAMN!

 

[Majakat]

If the iphone acts as a wireless access point the way you can get windows mobile phones to do with an addon - could they tell? using something like this-

(if it were available)

http://www.joiku.com/index.php?action=products&mode=productDetails&product_id=310

 

[RandomKamikaze]

Because the iPhone effectively acts as a NAT router when in tethering mode, it is technically possible to detect whether the TCP traffic has come straight from the phone - most simply by manipulation of the TTL (Time to Live) value in the packet: Whenever a TCP packet goes through a router, it's TTL value is reduced by one, but Apple could even have introduced a particular TTL value to identify tethered data.

So, for example, all traffic directly from iPhones coming into O2's gateways will probably have a TTL of 128. If it's from a tethered machine, the iPhone "router" will reduce that to 127 based on standard router behavior.

If Apple have been really sneaky, they could change it to something completely different to positively identify that your device is tethering to providers.

Don't forget that the first place any data on a mobile connection goes is through the equipment of your provider: They can find you out if they're so inclined...

Although your explanation was very good, it's not actually correct.

Your response makes it sounds like their is a private IP network between the iPhone and the computer, which there isn't. Nor does the iPhone act as a NAT router.

When you connect using tethering, the iPhone connects to the carriers network and then recevices an IP address. In the UK, these are private addresses. Obviously the iPhone connects to the Mac via USB cable or BT.

Therefore, inspecting the IP packets to look for a reduced TTL, which is also used to dictate the amount of time a packet can live, and not just how many routers it is allowed to pass through wouldn't work. There are however ways that are implemented within carriers networks to detect tethering, and one of those is an increase of traffic. Another could be to detect the type of traffic, or the port being used

 

[Phil A.]

Although your explanation was very good, it's not actually correct.

Your response makes it sounds like their is a private IP network between the iPhone and the computer, which there isn't. Nor does the iPhone act as a NAT router.

When you connect using tethering, the iPhone connects to the carriers network and then recevices an IP address. In the UK, these are private addresses. Obviously the iPhone connects to the Mac via USB cable or BT.

Therefore, inspecting the IP packets to look for a reduced TTL, which is also used to dictate the amount of time a packet can live, and not just how many routers it is allowed to pass through wouldn't work. There are however ways that are implemented within carriers networks to detect tethering, and one of those is an increase of traffic. Another could be to detect the type of traffic, or the port being used

I may be wrong because I've not really examined how iPhone tethering works in detail, but that's how Internet Sharing works on Windows Mobile devices (the device acts as a NAT router) and seeing as how the iPhone presents itself as a network port it's a fair bet it works the same: The device you are tethering has to get a network address from somewhere so it's either from the phone or the operator (it can't just use the phone's IP address)

 

[HiFiGuy528]

I think I ran up about 2GB since the hack on AT&T. Do you guys think this is just a scare tactic? I mean, can't you take them to court if they charge you the crazy rates per MB? You do have a "unlimited" data plan. I don't see anywhere on there site other than the multi page legal stuff saying there is a cap on "unlimited".

 

[RandomKamikaze]

I may be wrong because I've not really examined how iPhone tethering works in detail, but that's how Internet Sharing works on Windows Mobile devices (the device acts as a NAT router) and seeing as how the iPhone presents itself as a network port it's a fair bet it works the same: The device you are tethering has to get a network address from somewhere so it's either from the phone or the operator (it can't just use the phone's IP address)

Why not?

When you connect using USB or Bluetooth, you don't get an IP address.

In this case, and with WM devices and other phone's such as Nokia's, BlackBerry's etc, the device will connect to the carrier's network and receive the IP address for communication, then the laptop and device will just communicate with each other via USB or Bluetooth. As far as the carrier is concerned, they have only given out 1 IP.

 

[sziehr]

so from what i have read and gathered is the iphone actually has a modem hence the modem firmware. There is no router interface since it can only connect to one device at a time. Moding the TTL can screw with high volume network stacks a uniform TTL is easier to track at high speed. The fact they have no way to track the iphone is proof of the sudden tactics they are employing of scare and fear. The easist method would be your downloading 10 gigs of data on port 3100 not HTTP and not a known Streaming port for like pandora. Think about it these phones run on IPV4 there are only so many address that can be assigned even on a private cellular network so why let a device have two IP's when you can use it as a Tranciver. This mode would allow the phone to act as a media converter for the laptop and bridge the network gap that it is already residing on with it's cell IP.

 

[spaceballl]

Interesting... funny thing is that i'm pretty sure if they "disconnect" you, they can't charge you an ETF. That means that you get a phone for a great price and can join another carrier, get a phone through them, and sell one. Of course, probably still not worth being disconnected for... but still a perk!

 

[blucey]

I think I ran up about 2GB since the hack on AT&T. Do you guys think this is just a scare tactic? I mean, can't you take them to court if they charge you the crazy rates per MB? You do have a "unlimited" data plan. I don't see anywhere on there site other than the multi page legal stuff saying there is a cap on "unlimited".

They say you can't tether in the terms of service. :-(

"Furthermore, plans(unless specifically designated for tethering usage) cannot be used for any applications that tether the device (through use of, including without limitation, connection kits, other phone/PDA-to computer accessories, BLUETOOTH® or any other wireless technology) to Personal Computers (including without limitation, laptops), or other equipment for any purpose."

From:
http://www.wireless.att.com/learn/messaging-internet/media-legal-notices.jsp

 

[Tokiopop]

I've been tethering for months, they've sure caught me

 

[Phil A.]

Why not?

When you connect using USB or Bluetooth, you don't get an IP address.

In this case, and with WM devices and other phone's such as Nokia's, BlackBerry's etc, the device will connect to the carrier's network and receive the IP address for communication, then the laptop and device will just communicate with each other via USB or Bluetooth. As far as the carrier is concerned, they have only given out 1 IP.

OK, I temporarily enabled tethering to finally get to the bottom of this, and when you connect via USB or Bluetooth to the iPhone to tether, you do get an IP address - you get a new network port in your control panel (see attached image) and this has an IP address in the range 192.168.20.x with a router of 192.168.20.1 (which is your iPhone)
A simple traceroute with tethering enabled shows the packets going through the phone (192.168.20.1) and then on to O2's private network 172.16.192.x

This clearly shows that the iPhone does act as a router when tethering...

 

[bearcub76]

Cancelled

My tethering has definitely been stopped. Gutted, but understandable.

 

[jamesapp]

Ok so I updated to 3.0 I had been jb with 2.2.1 and I had been tethering for months with no problems. I am waiting for quickpwn 3.0 to come out to rejailbreak. I have a couple of questions about tethering, what is the chances of getting disconnected if I continue to tether with iPhone 3.0 firmware? What exactly does disconnect mean, does it mean I wouldn't be able to tether anymore? Does disconnect mean that I wouldn't be able to use the Internet on my iPhone?

 

[RandomKamikaze]

OK, I temporarily enabled tethering to finally get to the bottom of this, and when you connect via USB or Bluetooth to the iPhone to tether, you do get an IP address - you get a new network port in your control panel (see attached image) and this has an IP address in the range 192.168.20.x with a router of 192.168.20.1 (which is your iPhone)
A simple traceroute with tethering enabled shows the packets going through the phone (192.168.20.1) and then on to O2's private network 172.16.192.x

This clearly shows that the iPhone does act as a router when tethering...

Hm, I stand corrected. The screen shots are much appreciated.

I can honestly say that that is the first time that I have seen tethering implemented like that and I have tethered with Nokia's, BlackBerry's and a couple of WM devices. Does it do the same on Windows?

Is your iPhone Jailbroken? If it is, have you got Terminal installed? Can you do an ifconfig to show the interfaces during tethering and not? If not, don't worry, I would do it myself but am waiting for Ultrasn0w

 

[jck1634]

Well I've been tethering on and off since first using this hack last wednesday. So far, nothing bad to report. Haven't been charged for anything yet, nor been disconnected from the service.