Juniper MX480, Руководство по оборудованию

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Figure 31: Typical FPCs Supported on the MX480 Router
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DPCE-X-Q-40GE DPCE-X-Q-40GE
FPC3 MX-FPC2
MX-FPC2
If a slot is not occupied by a DPC, an FPC, or an SCB, a blank panel must be installed to
shield the empty slot and to allow cooling air to circulate properly through the router.
Each FPC supports up to two PICs. On an FPC2, one 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. On an FPC3, two Packet Forwarding
Engines receive incoming packets from the PICs installed on the FPC and forwards them
through the switch planes to the appropriate destination port. The FPCs interface with
the power supplies and SCBs.
FPCs are hot-removable and hot-insertable, as described in “MX480 Component
Redundancy” on page 34 . When you install an FPC into a functioning router, the Routing
Engine downloads the FPC software, the FPC runs its diagnostics, and the PICs, housed
on the FPC, are enabled. Forwarding continues uninterrupted during this process. When
you remove or install an FPC, packet forwarding between other DPCs or FPCs is not
affected.
FPC Components
Each FPC consists of the following components:
• FPC card carrier, which includes two PIC slots
•
Up to two Packet Forwarding Engines, each consisting of one I-chip for Layer 3
processing and one Layer 2 network processor
• Midplane connectors and power circuitry
• Processor subsystem (PMB), which includes a 1.2-GHz CPU, system controller, 1 GB of
SDRAM, and two Gigabit Ethernet interfaces
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Chapter 1: Overview