A:AnswerThis modem of modem is NOT an authorized modem for to replace your rented modem. Best way to find supported modems is to go to mydeviceinfo.xfinity.com
A:AnswerHi, CoastalCowboy. Since you already have a modem/router, adding another router will not help achieve the setup that you want. We suggest that you replace your device with a modem, before adding another Smart Wi-Fi router that has a 2.4GHz & 5GHz frequency.