T640 System Architecture Description; T640 Routing Engine Functions; Figure 1: Router Architecture - Juniper T640 Hardware Manual

T640 System Architecture Description

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T640 Routing Engine Functions

Copyright © 2017, Juniper Networks, Inc.
The router architecture cleanly separates control operations from packet forwarding
operations. This design eliminates processing and traffic bottlenecks, permitting the
router to achieve high performance. Control operations in the router are performed by
the host subsystem, which runs Junos OS to handle routing protocols, traffic engineering,
policy, policing, monitoring, and configuration management. Forwarding operations in
the router are performed by the Packet Forwarding Engines, which consist of hardware,
including ASICs, designed by Juniper Networks.
The T640 Core Router has two main architectural components:
Routing Engine—This component provides Layer 3 routing services and network
management.
Packet Forwarding Engines—These high-performance, ASIC-based components provide
Layer 2 and Layer 3 packet switching, route lookups, and packet forwarding.
The Routing Engine and the Packet Forwarding Engines perform their primary tasks
independently, although they constantly communicate through multiple 100-Mbps links.
This arrangement streamlines forwarding and routing control and runs Internet-scale
backbone networks at high speeds.
the Routing Engine and the Packet Forwarding Engines.

Figure 1: Router Architecture

T640 Chassis Description on page 15
The Routing Engine handles all routing protocol processes, as well as the software
processes that control the router's interfaces, the chassis components, system
management, and user access to the router. These routing and software processes run
on top of a kernel that interacts with the Packet Forwarding Engine.
The Routing Engine includes the functions and features:
Chapter 1: System Overview and Architecture
Figure 1 on page 5 shows the relationship between
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