An uplink port is a port on which transmit and receive are reversed, which is designed for inner-switch connection with a standard straight-through cable instead of a crossover cable. Thus, the uplink SFP port can connect to a regular port of another device. Plug the uplink SFP port of one Gigabit switch into the standard port of another Gigabit switch can help expand the network’s size. Most enterprise switches in the market contain 24 x RJ45 ports with 2 dedicated SFP uplink ports or 48 copper ports with either 2 or 4 dedicated SFP uplink ports. Each SFP uplink port has two lights that indicate activity and the status of that port.