Is your iPhone informing your netwok about tethering?

[3GScottishUser]

Interesting article in the Sunday Times today about sales of tablet devices and other equipment. Apparently 90% of tablets sold are without 3G or 4G modems built -in. Most are sold only with Wi-Fi because of the spread of smartphones that can become Wi-Fi hotspots.

The article went on to explain that Apple have some software on their iPhone that can hide the tethering facility unless you pay the network to allow it and further the iPhone can report tethering to networks where it can be viewed on the menu but has not been included in a price plan! Android handsets don't have that facility it was stated.

The point being made was not a bash at Apple but was an example of how mobile devices are changing and that the focus has to be shifted to Wi-Fi and tethering as a norm.

Has anyone come across an issue using an iPhone when tethering without it being part of a price plan?

[Wilt]

Sounds about right.

I do know that the tethering option can disappear unless you have a tethering plan on some network - I'm not so sure about the iphone passing this information on otherwise, though. But I wouldn't be surprised.

I know Three can sometimes detect tethering using DPI, and I believe this works no matter what operating system you're running.

[Ben]

The tethering option is hidden on the iPhone if the operator requests it. It's entirely possible that part of this works by the iPhone 'asking' the network if tethering is permitted.

Regarding tablets. I'd imagine a much greater proportion of non-Apple tablets are WiFi-only. However, even with the iPad the additional cost will severely limit the uptake of the version with cellular connectivity.

This, I feel, is likely to change with the arrival of LTE. 3G, God love it, just doesn't work well in so many situations. LTE should change that, and make patchy WiFi networks look truly horrific.

Greater interest in LTE-connected tablets will bring down the cost of the associated chippery and ultimately result in the feature being as standard as WiFi itself. You can have that little prediction FOC. ;)

[Hands0n]

My iPhone, on Vodafone, did not have the tethering option available, merely an advisory to contact Vodafone if I wanted it. A few weeks ago I updated my SIM only contract and upped the data to 1GB at which point Tethering was enabled on the iPhone, literally within minutes of completing the transaction in the store. So there is definitely a high degree of control that the operators can exercise over the iPhone.

Not so the Android and Windows Phone 7 devices, if their OS supports tethering. But then as Wilt has said, the networks can resort to DPI to find out exactly what you are doing and take action. Some have a fully automated robot response, others engage more humanely.

DPI is the right way to do it in the absence of global smartphone standards to manage network usage.

[DBMandrake]

The carrier settings bundle for each network in iOS (either built in or downloaded as updated carrier settings) includes all the settings that relate to Tethering.

The way most networks control Tethering access is by specifying a different APN for Tethering data and Phone data in the carrier settings bundle. Then to disable Tethering on the account they just disable the Tethering APN at the network end. If the phone tries to activate Tethering and the network rejects access to the APN the button is removed in the UI. Each time you go into the Tethering page under General->Network the phone will again attempt to activate the Tethering APN - if it succeeds the button is re-enabled in the UI. Simple as that...

Up until 3.1.3 it was possible to customise the carrier settings bundle (including custom Tethering APN) and upload it into the phone, now all the APN settings are signed by Apple so its not possible to do so.

For most networks they can tell that you're Tethering simply because the data is going through a separate APN - for those networks there is no way to "fool" them into thinking you're not Tethering when you are - they know for sure that you are.

Three are an interesting exception. For reasons that elude logic, they use the same APN for both Phone Data and Tethering Data, in fact even on an Android or other device its not possible to open a second data APN at the same time, and it has been like that for over a year. Because of this iPhone Tethering works on all Three plans whether you have a Tethering add-on or not, and its difficult (but not impossible) for them to know that you are Tethering.

The only way they can tell is by looking at browser user agents or otherwise analysing the traffic, meaning you typically get away with it if you don't abuse it.

I'm still on 3pay Pay&Go and although I don't use it much I've tethered both with the 1GB Internet max addon, and with the free 150MB blocks of data with topups and never had a problem or any warnings not to do it.... but then I haven't downloaded GB's of data. :)