- To find out the IP address, press OK on the keypad of your device (T48S).
- Open your web browser (such as Chrome, IE, or Firefox), enter the IP address in the address bar, and press enter.
- You will see the username and password prompt screen below. The default is admin/admin.
Go to Settings > Upgrade page.
You will see the firmware version of the device.
To download the appropriate firmware, go to the yealink support page.
- Find the appropriate model and download the firmware file with “.rom” file extension.
- Add the appropriate firmware version by clicking "browse". After the adding process is completed, you can click on the upload option and upload it.