Component Redundancy - Juniper SRX 5600 Hardware Manual

SRX 5600 Services Gateway Hardware Guide

Component Redundancy

The following major hardware components are redundant:
4
Component Redundancy
Management. This group of signals provides for low-level status diagnostic
support.
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
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
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.
PEM3 (left to right). Each AC power supply provides
PEM0