Juniper CBL-M40-PWR-AU ユーザーズマニュアル
Hardware Component Overview
Packet Forwarding Engine
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Figure 2: Rear View of Chassis
Packet Forwarding Engine
The Packet Forwarding Engine is a multicomponent system that uses application-specific
integrated circuits (ASICs) to perform Layer 2 and Layer 3 packet switching, route lookups,
and packet forwarding. The ASICs include the Distributed Buffer Manager ASIC, I/O Manager
ASIC, Internet Processor or Internet Processor II ASIC, and various media-specific controllers.
integrated circuits (ASICs) to perform Layer 2 and Layer 3 packet switching, route lookups,
and packet forwarding. The ASICs include the Distributed Buffer Manager ASIC, I/O Manager
ASIC, Internet Processor or Internet Processor II ASIC, and various media-specific controllers.
The Packet Forwarding Engine has the following components:
Backplane—Forms the rear of the FPC card cage, distributes power from the power
supplies, and transfers packets and signals between router components, which plug into
it.
it.
Physical Interface Cards (PICs)—Physically connect the router to network media such as
OC-12 ATM, OC-12 and OC-48 SONET/SDH, Channelized OC-12, and Gigabit Ethernet.
PICs are housed in FPCs.
PICs are housed in FPCs.
Flexible PIC Concentrators (FPCs)—Process incoming and outgoing packets. From one to
eight FPCs can plug into the backplane from the front of the chassis. Each FPC
accommodates up to four Physical Interface Cards (PICs).
accommodates up to four Physical Interface Cards (PICs).
System Control Board (SCB)—Performs route lookup, filtering, and switching. The SCB
installs into the backplane from the front of the chassis.
Routing Engine housing
Fan tray
Upper impeller assembly
Front rack-mounting ear
Center rack-mounting ear
LS-120 drive
Power supply A
Power supply B
ESD point
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