Yes. Your ISP-supplied modem may or may not have a built-in router, but it will usually have a spare ethernet port so you can plug in an external model. This external wireless router (such as the ones in our test) can be used instead of, or in addition to, the built-in wireless router. So if you have an older ISP-supplied modem/router you can still greatly increase your local network speed by plugging in a latest model wireless router. You can usually turn off the built-in wireless router in the device's settings.