Vilfo works independently of which internet service provider you have. However:
If you receive your internet connection from a coaxial cable, then you still need to use your existing modem/router that you have since Vilfo only supports ordinary ethernet cables. You can still use Vilfo in that case but you can't remove your existing modem/router. You would need to connect a cable from your current router/modem's LAN port into Vilfo's WAN port.
Do note that an IP collision may occur as your current router/modem might use the same IP span as Vilfo's default values. It is preferred if you're able to bridge the modem (setting it to an access point/bridge). That is however not possible if you also have VoIP, IP telephony or IPTV functionality that resides in the modem and which is used.
If you receive your internet connection from an ordinary ethernet cable, then you can definitely remove it and use Vilfo entirely instead.