Watch the physical LED indicators on the face of the unit. The behaves as your status tracker: Sagemcom 5866 modem status lights - iiHelp - iiNet

A: Yes, you can update your modem firmware using a mobile device, but ensure you have a stable internet connection.

Example format: SG5866-1.2.3.4-TMO or 5866.5G.B5.6 . Write this down. If your version ends with .0 or .1 , you are critically behind.