Currently have a Araknis Networks 110 Gigabit Switch for multiple computers to connect to the internet, do i need a router/modem?

Currently have a (Araknis Networks 110 Gigabit Switch), do i need a router/modem combo, or just a modem will work for multiple computers to connect to the internet from the switch?

I need a modem device for DATA & VOICE for phone (EMTA, DOCSIS 3.1) with bridge mode (Ability to turn off the WIFI)

Are the rented Infinity modems all have both modem/routers together?