Tethering your iPhone helps you to connect to the Internet, by plugging it in on a machine which has got Internet access, through a USB port, or connect it via Bluetooth. It helps you to browse internet in those conditions when you couldn’t find a WiFi hotspot to fulfill your needs.

It may also be helpful in those scenarios in which using WiFi on mobiles aren’t allowed. In that condition, the solution is to connect your laptop to WiFi and then hookup your iPhone via USB after enabling tethering. By doing this, you’ll be able to use Internet through WiFi on your iPhone.

Now how to enable it? The problem is that when you update your OS to 3.1.2, it disables the tethering, and in fact AT&T has blocked tethering for all iPhones recently. But if you’re interested in re-enabling it (after Jailbreaking of course), then Blacksn0w has just found a new solution which might be helpful for you.

Follow this step-by-step guide carefully to enable tethering on firmware 3.1.2 using Blacknow.

• First you need to Jailbreak your device. The related tutorial on how to Jailbreak iPhone 3.1.2 firmware can be found here.
• After that, launch Safari web browser on your iPhone and navigate to: http://m.peacefulinsanity.com/Tether.mobileconfig
• An install profile would open, which would ask you to install an unsigned US AT&T Tethering .IPCC file on your iPhone as shown in the snapshot below. Tap on Install

• Now reboot your iPhone by first holding down the Home button and Power button simultaneously until you see Apple logo on the screen.
• Once your iPhone has been restarted, simply navigate to Settings->General->Network->Internet Tethering on your iPhone and turn on Internet Tethering as shown in the picture below.

• You should now be able to connect to the Internet using Tethering.

If you have faced any problem during the whole process or have any sort of related questions in mind, then please feel free to leave a comment below!