The Cisco Catalyst 4500 Series Supervisor Engine II-Plus-10GE provides investment protection and an enhanced Layer 2 upgrade path to 10 Gigabit Ethernet. It includes dual wire-speed 10-Gigabit Ethernet ports (X2 optics) as well as 4 Gigabit Ethernet ports (SFP optics) on the faceplate. Both the 10-Gigabit X2 interfaces and the Gigabit SFP interfaces can be enabled simultaneously for maximum flexibility and scalability providing an easy migration path from Gigabit Ethernet to 10-Gigabit Ethernet. The Supervisor Engine II-Plus-10GE SDRAM is also optionally expandable from 256 MB to 512 MB for further scalability.