Cisco CRS-1 System Description page 53

Switch Fabric
Figure 25: \Block Diagram of the Cisco CRS 8-Slot Line Card Chassis Switch Fabric Card
The major functional blocks of the switch fabric card are as follows:
• S1 switch element: Receives data cells from the MSC (or RP) and distributes them to the S2 stage. The
S1 switch element is connected to its corresponding S2 switch element within the same fabric plane.
• S2 switch element: Receives data cells from the S1 stage. The S2 switch element is connected to its
corresponding S1 and S3 switch elements within the same fabric plane. S2 has 36 inputs and 36 outputs.
• S3 switch element: Receives data cells from the S2 stage and performs switching and fabric speed-up.
S3 has 36 inputs and 72 outputs.
• Service processor: Provides the interface to the Cisco CRS-1 control plane. The service processor does
the following:
• Controls power up and power down processes of the switch fabric card.
• Configures the components in the various switch elements.
• Updates the FGID (Fabric Group ID), for multicast traffic.
Cisco CRS Carrier Routing System 8-Slot Line Card Chassis Enhanced Router System Description
Switch Fabric Card Description
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