The Routing Engine is an Intel-based PC platform that runs JUNOS software. Software processes that run on the Routing Engine maintain the routing tables, manage the routing protocols used on the device, control the device interfaces, control some chassis components, and provide the interface for system management and user access to the device.
You can install only one Routing Engine in the device. The Routing Engine installs into the front of the chassis in the vertical slot in the SCB labeled 0 or 1.
A USB port on the Routing Engine accepts a USB memory card that allows you to load JUNOS software.
Figure 1: Routing Engine