Originally Posted by jabbamk1:
“They have auto detection methods like mentioned above. If you tether or are flagged as tethering you'll be redirected to a 3 tethering block page.”
Three normally detects Tethering by examining the HTTP headers sent by the customer and checking the
User Agent String
If it looks like the user is tethering, they'll get redirected to a page informing them of their options.
Originally Posted by wavejockglw:
“Apple have software included on their handsets that informs networks about tethering, Android does not”
It doesn't really work like that.
Apple use a system of "Carrier Settings" files. These contain settings specific to a mobile network (carrier in US terminology), such as: access point names, Voicemail numbers, links to the carrier's web page, MMS settings and the ability for the carrier to turn certain features of the device on or off.
One of the options carriers have is to choose whether or not the tethering option is enabled (branded as "Personal Hotspot" in more recent iOS versions).
This feature can only be used if the network is a "supported" network - O2, Vodafone, Three, T-Mobile, Orange and Tesco in the UK.
Talk Mobile would be detected as Vodafone, Virgin Mobile would be detected as T-Mobile.
The device doesn't actually report that the user is tethering - it simply allows the network to turn off a specific user's ability to use the feature.