M7i Router Components

Table 4 lists the major M7i router components and characteristics.

Table 4: M7i Router Major Hardware Components                    

Component	Quantity	Function	Redundant	Field- Replaceable	Offline Button
CFEB	1	Provides route lookup, management of shared memory, transfer of outgoing data packets, and transfer of exception and control packets; includes built-in tunnel interface and optional Adaptive Services PIC	-	Hot-pluggable (routing functions are interrupted when removed)	Yes
Cooling system	1 fan tray (4 fans)	Cools router components	-	Hot-removable, hot-insertable	-
FIC	1	Receives incoming packets and transmits outgoing packets to the network, displays alarm status, and takes PICs online and offline (2 Fast Ethernet or 1 Gigabit Ethernet)	-	Built-in	PICs On/Off button
PIC	1-4	Provides interfaces to various network media and performs framing and line-speed signaling	-	Hot-removable, hot-insertable	Yes
Power supply	2 AC or 2 DC	Distributes needed voltages to components	Yes	Hot-removable, hot-insertable	Yes
Routing Engine	1	Maintains the routing tables, manages the routing protocols, controls the interfaces, controls some chassis components, and provides the interface for system management and user access	-	Hot-pluggable (routing functions are interrupted when removed)	Yes

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—You can remove and replace the component without powering down the router or interrupting the routing functions.
• Hot-pluggable—You can remove the component without powering down the router, but routing functions are interrupted until the replacement is installed.
• Requires router shutdown—You must power down the router before removing the component.