Juniper PTX5000 Hardware Manual page 162

FPC Slots
Up to eight FPCs install vertically in the front of the PTX5000. The FPC slots are numbered FPC0
through FPC7, left to right. If a slot is not occupied by an FPC, an FPC blank panel must be installed to
shield the empty slot and to allow cooling air to circulate properly through the PTX5000.
FPC Function
FPCs house the PICs that connect the PTX5000 to network media. The main function of an FPC is to
connect the PICs installed in it to the other chassis components. The Packet Forwarding Engine receives
incoming packets from the PICs installed on the FPC and forwards them through the switch planes to
the appropriate destination port.
When you install an FPC into a functioning PTX5000, the Routing Engine downloads the FPC software,
the FPC runs its diagnostics, and the PICs housed on the FPC are enabled. Forwarding on other FPCs
continues uninterrupted during this process.
FPC Components
Each FPC consists of the following components:
• FPC card carrier
• Packet Forwarding Engines, consisting of Lookup ASICs and the Queuing and Memory Interface
ASICs
• Processor Mezzanine Board (PMB), which includes a 1.2-GHz CPU, 4 GB of SDRAM, and two Fast
Ethernet interfaces
• Two LEDs on the FPC that display the status of the FPC
• FPC online/offline button
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