I bought this system so I could hook up a verizon phone network extender via sattelite through the internet. The TP-Link device asks for a modem. I have fiber optic internet service that does not require a modem. It said somewhere to connect the fiber optic cable ditrectly to the node. Then I got a message that the network is not secure. I tried hooking up my old modem router, but that didn't work either. Is a modem required for this system to work?