Cisco Catalyst 4900 Series Switches are designed and optimized for the data center and top-of-rack aggregation. They offer industry-leading wire-speed performance, low latency with Layer 2-4 switching, innovative security features, Gigabit Ethernet or 10 Gigabit Ethernet uplinks, optional internal AC or DC 1 + 1 hot-swappable power supplies, and a hot-swappable fan tray with redundant fans.