There seems to be some confusion in the reviews about this cable modem. It is only a cable modem, not a router. It appears some people wanted to use both ports to have two separate devices connected. The two ports are there to enable link aggregation to achieve greater than 1 Gbps with supported routers. You will only be able to connect one router to this cable modem and the rest of your network will be plugged into your router and not the cable modem directly.
Would this work with Xfinity/Comcast tv/internet/telephone combined service? If not, do you have a device that would? Thanks.