Well you have two issues with that question, that are related but are two different issues. If your WIFI is weak or slow this will work well for you, a 5 bar signal in a very large 3 story home, the best part of this machine is the dual band WIFI side. The other part of your question applies to if this works with xfinity, well if xfinity use standard ethernet wiring, it should work fine. the xfinity wire should plug into the internet connector, and you then have four hard wired devices to plug into it with. I am not very pleased with my unit for other issues than yours, and its a big disappointment to me as I have used Linksys WRT 54's for years with never hardly a hick up. I have used the WIFI side of this unit and was impressed by its range and strong signal.