This will NOT speed-up your internet. Your internet speed depends on what speed you paid for through your ISP. You will need a router if your internet is connected to a computer only through the modem. Also, Xfinity provides a modem/router combo. Always make sure your equipment is compatible with your level of service. The equipment is always a 'choke point' for internet speed. Your equipment should always, at least match the speed you're paying for. Your best bet is to have equipment that has room for more bandwidth just in case your ISP boosts their service speed.