Most ISPs can push the firmware remotely via (remote management). You do not need to download anything; they push it over the fiber line.
: The firmware manages two POTS ports for telephony and USB ports for DLNA media sharing across a home network. Evolution and Versioning
Most users never think about firmware until something breaks. However, updating your ZTE F680 firmware (or ensuring it is up to date) offers several critical benefits:
Most ZTE F680 units support an automated update process through the web interface. Access the Admin Page : Open your browser and go to 192.168.1.1 192.168.0.1 : Enter your credentials (default is often or printed on the router label). Navigate to Management Device Management Firmware Upgrade (or Update Management). Check for Updates