A system and method for increasing input/output speeds in a network switch. A physical layer device is provided that includes a physical coding sublayer that insert data flow identifiers to data flows that are provided to a gearbox. In one embodiment, the gearbox is a 5 to 2 gearbox that can transport various combinations of 10G/40G data flows over a narrower interface to a second physical layer device having an inverse gearbox.