Cisco Systems XR 12404 manual Power Entry Modules, Switch Fabric Functionality

Chapter 1 Cisco XR 12404 Router Overview

Power Entry Modules

Switch Fabric Functionality

Switch fabric circuitry provides up to 40 Gbps (full duplex) of synchronized speed interconnections that carries user traffic between line cards or between the route processor and the line cards.

Clock and Scheduler Functionality

The fabric card generates and distributes system-wide clock and cell time synchronization signaling. System clock generation is delivered to the system through the backplane and local clock functions are derived from the system clock.

•System Clock—The system clock synchronizes data transfers between line cards or between the route processor and a line card through the CSF. The system clock signal is sent to all line cards and the route processor.

•Scheduler—The scheduler handles requests from the line cards for access to the CSF. When the scheduler receives a request from a line card for CSF access, the scheduler determines when to allow the line card access to the CSF.

Power Entry Modules

The Cisco XR 12404 router chassis supports two hot swappable AC or DC PEMs. The router must be populated with 2 PEMs to meet EMI standards.

Caution Do not mix PEM types in the router. PEMs must be the same type; either both AC PEMs, or both DC PEMs and PDUs.

	Cisco XR 12404 Router Installation Guide
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