I have my router and VHM&C gateway on a UPS. But the problem is the FIOS Interface box (the wall mounted unit which converts the fiber optic coming from the street) does not have a UPS backup which supplies power to the whole box. The battery backup in the FIOSInterfacebox is only there to keep the phone system running in case of an outage. Because of this, if you lose power your Internet will go down and can sometimes brain-freeze your VHM&Cgateway.
One solution is to put an external UPS on the FIOS Interface box in addition to putting one on the routerandVHM&Cgateway.
Since I have my routerandVHM&Cgateway up in the attic (I live in a one story older home with very thick walls. Putting the router and VHM&C gateway in the attic, which is a simple wooden roof, allows my WiFi to cover my entire property.), I put a remote power switch on the VHM&Cgateway so I can reboot it easily.
But even without any power outage, the VHM&Cgateway can lock-up from time to time.