SRX5600 Services Gateway Component Redundancy

The following major hardware components are redundant:

• SCBs—The host subsystem consists of a Routing Engine installed in an SCB. The device must have one host subsystem installed. You can install a second SCB for redundancy. If a second SCB is installed, the host subsystem SCB functions as the master and the other functions as the backup. If the SCB of the host subsystem fails, the other SCB takes over as the master.
• Power supplies—In the low-line (110 V) AC power configuration, the device contains three or four AC power supplies, located horizontally at the rear of the chassis in slots PEM0 through PEM3 (left to right). Each AC power supply provides power to all components in the device. When three power supplies are present, they share power almost equally within a fully populated system. Four AC power supplies provide full power redundancy. If one power supply fails or is removed, the remaining power supplies instantly assume the entire electrical load without interruption. Three power supplies provide the maximum configuration with full power for as long as the device is operational.

  In the high-line (220 V) AC power configuration, the device contains two or four AC power supplies located horizontally at the rear of the chassis in slots PEM0 through PEM3 (left to right). Each AC power supply provides power to all components in the device. When two or more power supplies are present, they share power almost equally within a fully populated system. Four AC power supplies provide full power redundancy. If one power supply fails or is removed, the remaining power supplies instantly assume the entire electrical load without interruption. Two power supplies provide the maximum configuration with full power for as long as the device is operational.

  In the DC configuration, two power supplies are required to supply power to a fully configured device. One power supply supports approximately half of the components in the device, and the other power supply supports the remaining components. The addition of two power supplies provides full power redundancy. If one power supply fails or is removed, the remaining power supplies instantly assume the entire electrical load without interruption. Two power supplies provide the maximum configuration with full power for as long as the device is operational.

• Cooling system—The cooling system has redundant components, which are controlled by the host subsystem. If one of the fans fails, the host subsystem increases the speed of the remaining fans to provide sufficient cooling for the services gateway indefinitely.