M160 Internet Router Hardware Guide
Field-Replaceable Units (FRUs)
Field-replaceable units (FRUs) are router compo nents that can be replaced at
the customer site. Replac ing most FRUs requires minimal router downtime.
The router uses the following types of FRUs:
Hot-removableandhot-insertableFRUs—Youcanremoveandreplacethese
components without powering down the rout er 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.
Table 4 lists the FRUs for the M160 router.
Table 4: Field-Replace able Units
Hot-Removable and
Hot-Insertable FRUs Hot-Pluggable FRUs
FRUs That Require Powering
Down the Router
Air filter
Fan tray ( locate d behind
the cable management
system)
Flexible PIC Concentrator
(FPC)
Physical Interface Card
(PIC)
Power sup ply
Small form factor
pluggable (SFP)
Miscellaneous Control
Subsystem (MCS)
Packet Forwarding Engine
Clock Generator (PCG)
Routing Engine
Switchingand Forwarding
Module (SFM)
Circuit breaker box
Connector Interface Panel (CIP)
For FRU replacement instructions, see “Replacing Hardware
Components” on page 139.
System Redundancy
The router is designedso that no single point of failure can cause the entire system
to fail. The fol lowing hardware components cont ribute 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 becomesexcessive—for example, becausea
cooling system component is removed—the MCS automatically increases the
speed of the remaining components to reduce the temperature. The cooling
4System Redundancy