The TL-WR841N is just a router. It is not a gateway (router/modem combo). Depending on how you get your internet, you may not need a modem which may happen with apartments or student housing. Your ISP (internet service provider) will be able to provide you with a list of approved modems or gateways if you need one. If you are replacing just the TL-WR841N, then all you need is a router, not a gateway.