I finally figured out why my connection has some outages. There are 2 causes for this - and I'm afraid I can fix only one. The Modem I have sometimes gets a hickup - and stalls. This one needs a hard-reset. I'll probably hook up a timer onto it's power supply to get it fixed. The other issue is a software issue on the firewall/router. The built-in hardware watchdog will go into shutdown mode instead of reboot mode - forcing a normal shutdown. Only a regular power-cycle can fix that one. However in the latter case, a firmware fix is out I still have to apply. and - for all issues, I'll hook up that firewall router to the timer to also get it power cycled once a day at dawn. This way - connectivity should be there during the day.

Update: Updated the firmware of the router. A 2 Minute operation. Easy. Will see if the watchdog reboots are stable now.