Juniper PTX5000, Hardware Manual

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Switch Interface Boards (SIBs) 9
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Chassis grounding points
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Control Board CB0 and Routing Engine RE0
SEE ALSO
PTX5000 Chassis Description | 14
Overview of Installing the PTX5000 | 197
PTX5000 System Architecture Description
The PTX5000 has two main architectural components:
• Routing Engine—One or more Routing Engines provide Layer 3 routing services and network
management.
• Packet Forwarding Engines—These high-performance, ASIC-based components provide packet
forwarding, route lookups, and Layer 2 and Layer 3 packet switching. See "PTX5000 Packet
Forwarding Engine Architecture" on page 6 for more information.
The Routing Engines and the Packet Forwarding Engines perform their primary tasks independently, but
communicate through multiple links. This arrangement streamlines forwarding and routing control and
runs Internet-scale backbone networks at high speeds.
PTX5000 Packet Forwarding Engine Architecture
The Packet Forwarding Engines provide Layer 2 and Layer 3 packet switching, forwarding, and route
lookup functions.
The Packet Forwarding Engines are implemented in ASICs that are physically located on the FPCs. Each
Packet Forwarding Engine consists of the following components:
• Lookup ASICs, which provide the route lookup function, control functions, Layer 2 and Layer 3
encapsulation and de-encapsulation, and manage the division and reassembly of packets within the
PTX5000.
• Queuing and Memory Interface ASICs, which manage the buffering of data cells in memory and the
queueing of notifications.
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