Juniper CBL-M40-PWR-AU ユーザーズマニュアル

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Field-Replaceable Units (FRUs)
M40 Internet Router Hardware Guide
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Field-Replaceable Units (FRUs)
Field-replaceable units (FRUs) are router components that can be replaced at the customer 
site. Replacing FRUs requires minimal router downtime. There are three types of FRUs:
„ Hot-removable and hot-insertable FRUs—You can remove and replace these 
components without powering down the router or disrupting the routing functions.
„ Hot-pluggable FRUs—You can remove and replace these components without powering 
down the router, but the routing functions of the system are interrupted when the 
component is removed.
„ FRUs that require powering down the router—You must power down the router before 
removing these components.
Table 2 lists the FRUs for the M40 router.
Table 2:  Field-Replaceable Units
Component Redundancy
The router is designed so that no single point of failure can cause the entire system to fail. 
The following hardware components contribute to system redundancy:
„ Cooling system—When the temperature inside the router is below the acceptable 
maximum, the cooling system’s components function at less than full speed. If the 
temperature becomes excessive—for example, because a cooling system component is 
removed—the SCB automatically increases the speed of the remaining components to 
reduce the temperature. The cooling system can function at the higher speed 
indefinitely. For more information, see “Cooling System” on page 23.
„ Power supply—The router has two load-sharing power supplies to distribute power to the 
other components. If one power supply fails, the second power supply can provide full 
power to the router's components indefinitely. For more information, see “Power 
Supplies” on page 20.
Hot-Removable and 
Hot-Insertable FRUs
Hot-Pluggable FRUs
FRUs That Require Powering 
Down the Router
„ Fan tray assembly
„ Flexible PIC Concentrator 
(FPC)
„ Front and rear impeller 
assemblies
„ Physical Interface Card 
(PIC)
„ Power supply
„ Routing Engine
„ System Control Board 
(SCB)
„ Craft interface