Field-Replaceable Units (Frus); System Redundancy; Table 4: Field-Replaceable Units - Juniper Internet Router M160 Hardware Manual

M160 Internet Router Hardware Guide

Field-Replaceable Units (FRUs)

Field-replaceable units (FRUs) are router components that can be replaced at
the customer site. Replacing most FRUs requires minimal router downtime.
The router uses the following types of FRUs:
Table 4 lists the FRUs for the M160 router.

Table 4: Field-Replaceable Units

Hot-Removable and
Hot-Insertable FRUs
Air filter
Fan tray (located behind
the cable management
system)
Flexible PIC Concentrator
(FPC)
Physical Interface Card
(PIC)
Power supply
Small form factor
pluggable (SFP)
For FRU replacement instructions, see "Replacing Hardware
Components" on page 139.

System 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:
4
System Redundancy
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.
Hot-Pluggable FRUs
Miscellaneous Control
Subsystem (MCS)
Packet Forwarding Engine
Clock Generator (PCG)
Routing Engine
Switching and Forwarding
Module (SFM)
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 MCS automatically increases the
speed of the remaining components to reduce the temperature. The cooling
FRUs That Require Powering
Down the Router
Circuit breaker box
Connector Interface Panel (CIP)