Chapter1 Cisco XR 12406 Router Overview
Line Cards
1-12
CiscoXR 12406 Router Installation Guide
OL-13831-01

Switch Fabric Redundancy

Equipping the router with two CSCs provides data path, scheduler, and reference
clock redundancy. The interfaces between the line cards and the switch fabric are
monitored constantly. If the router detects a loss of synchronization (LOS), it
automatically activates the data paths of the redundant CSC, and data flows across
the redundant path. The switch to the redundant CSC occurs within 0.5 second,
with little or no loss of data.
Note The enhanced Cisco XR 12406 chassis (XR-12000/6 configured with 1 2406/120
fabric option) ships with redundant CSC which is required to maintain High
Availability for the system.
Alarm Cards
The Cisco XR 12406 Router has two alarm card slots (Figure 1-5). Each alarm
card performs the following function or indicates the following cond ition:
•Alarm output
•CSC status
•SFC status
•Alarm card status
•Power source and power entry module status
•Alarm relay contacts
The entire alarm function has been implemented on redundant alarm cards with
OIR maintenance (hot-swappable) functionality.