Bridge/Router Installation Guide

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Cisco CRS-1 Carrier Routing System 4-Slot Line Card Chassis Installation Guide
OL-10971-07
Chapter 1 Overview
Chassis Components
• One or two route processor cards (RPs). The RPs function as the Cisco CRS-1 4-slot line card
chassis system controller and provide route processing.
Only one RP is required for system operation. For redundant operation, you can order a second RP
as an option (CRS-4-RP/R). When two RPs are used, only one RP is active at a time. The second RP
acts as a “standby” RP, serving as a backup if the active RP fails.
The RP also monitors system alarms and controls the system fans. LEDS on the front panel indicate
active alarm conditions.
• Fan tray. The fans pull cool air through the chassis. A removable air filter is located below the PLIM
card cage at the front of the chassis. The fan tray has four fans that provide n+1 redundancy.
• Four switch fabric cards (SFCs). These cards provide the three-stage Benes switch fabric for the
routing system. The switch fabric performs the cross-connect function of the routing system,
connecting every MSC (and its associated PLIM) with every other MSC (and its associated PLIM)
in the system.
The switch fabric receives user data from one MSC and PLIM pair and performs the switching
necessary to route the data to the appropriate egress MSC and PLIM pair. The switch fabric is
divided into eight logical planes (four physical planes) that are used to evenly distribute the traffic
across the switch fabric. Each switch fabric card implements two planes of the switch fabric.
• A power system that provides redundant power to the chassis. The power system consists of an AC
power shelf, which contains four AC rectifier modules, or a DC power shelf, which encloses four
DC power supplies. The power shelf (AC or DC as ordered) is pre-installed in the chassis when you
receive the routing system.
The PLIM side of the chassis is considered the front of the chassis, where user data cables attach to the
PLIMs and cool air enters the chassis. The switch fabric card side, which is where warm air is exhausted,
is considered to be the rear of the chassis.