Router Installation Guide

Chapter 1 Product Overview
Switch Fabric Overview
1-16
Cisco XR 12416 Router Installation Guide
OL-13833-01
Switch Fabric Overview
The switch fabric provides synchronized gigabit-speed connections between line
cards and the RP. The switch fabric card cage is located behind the air filter door
and consists of 2 clock and scheduler cards (CSCs) and 3 switch fabric cards
(SFCs). One CSC and the 3 SFCs are the active switch fabric; the second CSC
provides redundancy for the other 4 cards.
Note 10-Gbps switch fabrics do not operate in 1/4-bandwidth mode as they did in some
earlier models of the Cisco 12000 series routers. You must have at least one CSC
and three SFCs for the system to function. You can add an additional CSC for
redundancy.
Each SFC or CSC provides 10-Gbps full-duplex connection to each line card in
the system. For example, in a Cisco XR 12416 router with 16 line cards, each with
2 x 10 Gbps capacity (full duplex), the system switching bandwidth is 16x 20
Gbps = 320 Gbps.
Note The Cisco XR 12416 router supports online insertion and removal (OIR), which
allows you to remove and replace a card while the router remains powered on.
Switch Fabric Card Functionality
The core of the router is a crossbar switch fabric that provides synchronized
connections between the line cards and the RP. The switch fabric consists of 2
clock scheduler cards (CSCs) and 3 switch fabric cards (SFCs) installed in the
switch fabric card cage. One CSC and the three SFCs are the active switch fabric;
the second CSC provides redundancy for the other 4 cards.
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.