2 Excellent Software to Monitor Internet Usage in Windows
monitor-io: Continuously Monitor Your Internet Service and IoT Connectivity - for Homes, Businesses, and Installers | Receive Service and Device Alerts | Remotely Diagnose Issues | No Monthly Fee : Amazon.in: Computers & Accessories
WiFi Monitor
linux - How to monitor two internet connections to detect outages and switch to the active one when one is down - Super User
How to use LiveData to monitor an internet connection | by Rey | AndroidGeek.co | Medium
How To Monitor Internet Connection Stability In Windows