The Catalyst 4006 chassis offers flexible six-slot modular chassis, with one slot reserved for a supervisor engine and five remaining slots for switched port modules. Its three power supply bays support redundant (option), load-sharing, fault-tolerant AC or DC power supplies.The Cisco Catalyst 4006 Supervisor Engine II-Plus delivers intelligent network services and control required for a converged wiring closet while also offering high-performance Layer 3/4 switching capabilities to allow for deployment in small backbones or Layer 3 distribution points. The Supervisor Engine II-Plus offers an extensive feature set with the simplicity of traditional LAN switching, multilayer services such as IP routing, advanced QoS, sophisticated traffic management, improved security, and simple management.