XAUI (a concatenation of the Roman numeral X, meaning ten, and the initials of "Attachment Unit Interface") is a standard for connecting 10 Gigabit Ethernet (10GBE) ports to each other and to other electronic devices on a printed circuit board. It is designed to the IEEE 802.3ae 10GBE specification. It is intended as a convenient 16-pin replacement for the 72-pin 10 Gigabit Medium-Independent Interface (XGMII ) also used to route 10GBE signals on a circuit board. For example, a network switch may have many 10GBE ports, perhaps of different types, but must have the capability to connect any port to any other port. If all these ports are XAUI types, then the same electronic switches can be used to interconnect any of the ports using a minimum number of circuit wires.