No. Any wireless router can be connected to your Xfinity Modem to expand your networks functionality. There is a port on the router, which is clearly marked, that is used for the internet. You just need to plug a cat6 ethernet cable into a jack on the modem an into the internet port on the router then attach the router to your computer and follow the instructions. If you don't have a cat6 cable or are not sure what that is (it is stamped on the outside of the cable) you can still use any other cable, such as the one that comes with the router, that will fit but it may lose some speed if the cable is too long.