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Cisco XR 12404 Router Installation Guide
OL-13830-02
Chapter1 Cisco XR 12404 Router Overview
Route Processor
•ACpower en try module (PEM)—A customized and hot-swappable on e-piece
unit. See the “Power Entry Modules” section on page 1-17 for information.
•DC power entry module (PEM) and DC power distribution unit (PDU)—Two
pieces that can be removed as one unit or in separate pieces. See the “Power
Entry Modules” section on page 1-17 for information.
Note When operating the router, both power module bays must have DC PEMs
and DC PDUs installed to ensure EMI compliance.
•Fan tray assembly—Supplies cooling air to the router. See the “Fan Tray
Assembly” section on page 1-20 for information.
•Cable management bracket used to neatly route line card cables. See the
“Cable Management System” section on page 1-22 for information.
•Maintenance Bus—Controls all of the MBus modules in the system. See the
“Maintenance Bus” section on page 1-24 for information.
Route Processor
The route processor for the Cisco XR 12404 router is the Pe rformance Route
Processor (PRP-2). For detailed information about the PRP-2, 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-on
•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
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