Cisco Systems XR 12410 manual Switch Fabric Card Functionality, Clock Scheduler Card

Chapter 1 Cisco XR 12410 Router Overview

Switch Fabric and Alarm Card Overview

Switch Fabric Card Functionality

Routers ship from the factory with 2 CSCs and 5 SFCs installed in the 7 slots in the switch fabric and alarm card cage (see Figure 1-2).

•CSCs are installed in slot 0 (CSC0) or slot 1 (CSC1).

•SFCs are installed in slot 2 (SFC0), slot 3 (SFC1), slot 4 (SFC2), slot 5 (SFC3), and slot 6 (SFC4).

Note The enhanced version of the CSC and SFC cards is required for support of BITS, Single Router APS and Dual Priority features. The enhanced version of the cards cannot be mixed with the original version fabric cards.

Clock Scheduler Card

Clock scheduler cards provide the following functionality:

•Scheduler—Handles all scheduling requests from the line cards for access to the switch fabric.

•System clock—Supplies the synchronizing signal to all SFCs, line cards, and the RP. The system clock synchronizes data transfers between line cards or between line cards and the RP through the switch fabric.

•Switch fabric—Carries user traffic between line cards or between the RP and a line card. The switch fabric on the CSC is identical to the switch fabric on the SFC.

The second CSC provides redundancy for the data path, scheduler, and reference clock. Traffic between the line cards and the switch fabric is monitored constantly. If the system detects a loss of synchronization (LOS), it automatically activates the data paths on the redundant CSC so data flows across the redundant paths. The switch to the redundant CSC occurs within sub-seconds (the actual switch time depends on your configuration and its scale).

	Cisco XR 12410 Router Installation Guide
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