The Allied Telesis AT-RPS3104 and AT-PWR3101 switch accessories provide optional redundant power options to a range of Allied Telesis switches. Installing a redundant power supply increases network reliability, as the switch can continue to operate in the event of a failure of the switch's main internal power supply, or that of the redundant power supply. Failure of either power supply causes an event to be sent to a Network Management System (NMS) allowing a network administrator to take the appropriate remedial action, thus averting a catastrophic failure on the network.The AT-RPS3104 is a 19in rack-mountable chassis, capable of holding up to four individual AT-PWR3101 power modules.