Aastra 9112i firmware
Aastra 9133i firmware
Aastra 480i firmware

Unzip the file in a directory you will be able to remember.

3. Download the TFTP application and install it on your PC.

4. To setup the TFTP application:

Run the TFTP application and click on Server->Properties...
Click on the General tab and enter the full path to the location of the firmware files downloaded above in the Default directory field (eg C:\My Documents\aastra_firmware).
Also enable the Overwrite if file exists option.
Press OK to save your changes.

5. You now have to configure the phone to download the firmware files from your PC, using TFTP. You can do this using the phone menu or the web configuration pages.

Configuring TFTP using the phone menu:

Press the Options button
Scroll down to Option 9 "Network"
Enter the Admin password at the prompt (default is 22222)
Scroll down to option 7 "TFTP Server"
Press "Show" button on the screen and then again against Primary TFTP Server
Enter the TFTP IP Address (ie the IP Address of your PC retrieved in Step 1). < > keys can be used to scroll between the dot fields on the screen
Press the Done on the screen
Reboot the phone. During the reboot, the phone will download the firmware from your PC.

Configuring TFTP using the web configuration menu:

Type the Aastra device's IP Address in your web browser
Enter the admin user details, default password is 22222
Click on the Firmware update link on the lefthand side of the page
Enter the IP address of the TFTP server (ie the IP Address of your PC retrieved in Step 1) in the TFTP Server IP field.
Enter the firmware filename which is determined by the model of your phone:

-Aastra 480i: 480i.st
-Aastra 9112i: 9112i.st
-Aastra 9133i: 9133i.st