Chapter1 Cisco XR 12406 Router Overview
Physical and Functional Description
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CiscoXR 12406 Router Installation Guide
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Physical and Functional Description
The following are the main components that make up the Cisco XR 12406 Router:
•One route processor with a second (redundant) route proce ssor option
•Up to 5 line cards (4 if there are redundant route p rocessors)
•2 clock scheduler cards (CSCs)
•3 switch fabric cards (SFCs)
•2 alarm cards
•2 power modules
•Backplane and maintenance bus
•Blower module
•2 air filters
These components and their functions are described in this section. See Chapter5,
“Maintaining the Router” for instructions to remove and replace the FRUs.

Route Processor

The route processor for the Cisco XR 12406 Router is the Pe rformance Route
Processor (PRP-2). For detailed information about the Performance Route
Processor, refer to the Cisco document, Performance Route Processor Installation
and Configuration Guide.
The PRP-2 performs the following primary functions:
•Executes routing protocol stacks
•Performs all protocol communications with other routers
•Builds and distributes forwarding information to all line cards
•Uploads the operating system software images to all installed line cards
during power-up
•Provides out-of-band system console and auxiliary ports and an Ethernet port
for router configuration and maintenance
•Monitors and manages the power and temperature of system components
such as line cards, power supplies, and fans