Clock Scheduler Cards; Switch Fabric Cards - Cisco 12416 Installation And Configuration Manual

Switch Fabric Overview
Caution

Clock Scheduler Cards

Switch Fabric Cards

Cisco 12016, Cisco 12416, and Cisco 12816 Router Installation and Configuration Guide
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The router also ships with a blank switch fabric card installed in the far left
(non-working) slot of the switch fabric card cage. The blank filler panel balances
the air flow through the switch fabric card cage which helps maintain proper air
flow through the chassis.
Do not remove the blank filler panel unless instructed to do so by a Cisco support
representative.
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 the 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 The switch to the redundant CSC
occurs within sub-seconds (the actual switch time depends on your configuration
and its scale).
The switch fabric cards augment the traffic capacity of the router. SFCs contain
switch fabric circuitry that can only carry user traffic between line cards or
between the RP and the line cards. SFCs receive all scheduling information and
the system clock signal from the CSCs.
Chapter 1 Product Overview
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