The Control Board (CB), which runs Juniper Networks Junos operating system, works with the RE to provide control plane and chassis management functionality while maintaining RoHS compliance. Software processes running on the RE manage the routing tables, while the protocols running on the switch control all of the interfaces, manage chassis functions, and provide the interface for system management and user access. The system can house two RE/CB complexes, with one acting as the primary and the other acting as the standby ready to take over in case of failure. The RE communicates with the CB via a pair of 10GbE links and a Peripheral Component Interconnect (PCI) bus.