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Cisco AS5850 Universal Gateway Hardware Installation Guide
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Chapter1 Cisco AS5850 Product Overview
Field-Replaceable Units
Feature Cards
For information about the feature cards used in the Cisco AS5850, refer to the Cisco AS5850 Universal
Gateway Card Guide that shipped with your system. For information about other FRUs, review the rest
of this chapter, or for detailed specification tables, refer to AppendixA, “Cisco AS5850 Specifications”
Cooling Module
The cooling module in the CiscoAS5850 monitors the internal operating temperatures and maintains
acceptable cooling parameters. The cooling module contains 12 variable-speed impeller fans in three
banks of four fans, and a controller card that performs the following functions:
•Monitors internal temperatures
The controller card contains temperature sensors, that monitor internal air temperature within the
chassis. These temperature sensors, along with other system maintenance sensors, can detect areas
exceeding the temperature set point.
•Controls fan operation
Fan speed is controlled by a microprocessor on the fan controller card within the cooling module,
and also by software. If air temperature within the chassis exceeds the acceptable operating range,
the fan controller card increases the fan speed in an attempt to control the temperature. If
temperatures continue to rise, the controller card linearly increases fan speed until the fans reach full
speed. If acceptable operating temperatures are still unobtainable, the system environmental monitor
shuts down all internal power, thus preventing equipment damage from excessive heat.
During normal operation, the fans “load-share” to provide cooling. If one of the twelve fans fails, a
warning message displays on your console screen. The controller card then increases the speed of
the remaining operative fans to maintain acceptable temperature levels.
When all fans are operating normally, fan speed is 1600 rpm. As ambient air temperature increases,
fan speed increases accordingly. Thus, if one of the fans becomes inoperative, the remaining fans
increase fan speed to 2400 rpm.
•Supports OIR
The cooling module supports OIR, which means that you can remove and replace the cooling
module while the system is operating; system operation will not be affected. Normal cooling module
replacement should take about 30 seconds. If you expect the replacement process to exceed 1
minute, you should shut down the system.
The cooling module is located directly above the feature cards. You install the cooling module into the
front of the chassis where it plugs directly into the PEMFs. Figure1-1 on shows the location of the
cooling module in a fully configured CiscoAS5850 chassis, as viewed from the front of the system.
For detailed specification tables, refer to AppendixA, “Cisco AS5850 Specifications.”
Route Switch Controller Card
The route switch controller (RSC) card is the main processor card for the universal gateway. There is
also an enhanced route switch controller (ERSC) that has a faster CPU, more memory and two Fast
Ethernet ports for network management. Both cards perform the following functions:
•Transfers data as Fast Ethernet or gigabit Ethernet packets encapsulated in proprietary protocol
•Provides high availability when configured in handover-split or RPR+ mode