The Cisco Catalyst 4900M Series is a premium extension to the widely deployed Cisco Catalyst 4900 Series top-of-rack Ethernet switch specifically designed for data center networks. Optimized for ultimate deployment flexibility, the Cisco Catalyst 4900M can be deployed for 10/100/1000 server access with 1:1 uplink-to-downlink oversubscription and a mix of 10/100/1000 and 10 Gigabit Ethernet servers or all 10 Gigabit Ethernet server environments. The Cisco Catalyst 4900M is a 320-Gbps, 250 million packets per second, two-rack-unit (2RU) fixed-configuration switch with 8 fixed wire-speed X2 ports on the base unit and 2 optional half-card slots for deployment flexibility and investment protection. Low latency, scalable buffer memory, and high availability with 1+1 hot swappable AC or DC power supplies and a field replaceable fan tray optimize the Cisco Catalyst 4900M for any size of data center.