Advanced - QoS/Security (Tab) - USB Storage(Section): Allow Software Update
The settings enables that a software update can be done using a USB storage. If the setting is on and a USB storage is plugged in which hold a Snom firmware in the root directory, the phone will indicate that a software update is available and the user can chose to install it. If the USB storage holds more that one firmware for the phone type the first one will be picked and no selection will be shown. The setting requires administrator mode. The feature is available on all phones with a USB port.