If you are having a SFR Illimythics or Carre unlimited data plan, you must have realized that the standard Android Wifi Hotspot is almost unusable with your other devices. You can connect to your Wifi Hotspot but all the pages are blank !
This comes from the fact that operators like SFR decided to block internet connection sharing by analysing all the data you send and by checking the User Agent declared by your browser. If the User Agent is known and accepted by the operator, the packet is carried. If not it is simply dropped. You will then get a blank page on your browser.
With a Postal comparison, its like if your postal service is starting to read every letter you send and decides to carry it or not according to what you have written ! Unbelievable … but true.
This behaviour comes from the business model mobile operators are trying to build : they expect to be able to shave an egg ! When they sell you an unlimited 3G mobile data plan for your smartphone, they want to sell you a second one for your tablet, a third one for your laptop, … This is highly logical as everybody knows that with two hands and two eyes you can surf on four devices at the same time !
Hopefully, this can be circumvented with a very simple tool : Firefox. This article explains the simple steps needed to be able to bypass SFR User Agent filtering which blocks connexion sharing. It works with any device running Firefox browser. You will then be able to use Android inbuilt Wifi Hotspot feature as it was always supposed to be used.
This connexion sharing has been tested with devices running Firefox 19+ under Ubuntu 12.04, Windows 7 and Android 4.2.