Cisco 12008, Installation And Configuration Manual, Page: 97 / 382

Product Overview 1-75
System Specifications
The MBus modules on other installed components then power up on command from the
master MBus agent on the GRP.
•
Device discovery—The GRP determines the system configuration by means of the
MBus facility.
A message is sent from the master GRP MBus agent, requesting that all installed
components identify themselves. Each return response includes slot number, card type,
and component type.
•
Downloading software—A line card ROM monitor is loaded into Flash ROM on the
card during the manufacturing process. This image, which can be field upgraded, if
necessary, boots software to the line card by means of the MBus facility.
Because the MBus is slow relative to the switch fabric, only enough code is initially
downloaded to the line card to enable it to access the router’s switch fabric.
This initial code includes a line card fabric downloader that functions as a secondary
bootstrap program to quickly complete the downloading of the Cisco IOS image to the
line card by means of the router’s high-speed switch fabric.
•
Diagnostics—The MBus facility enables field diagnostics to be run on the GRP and the
line cards, whether the router is in service (running diagnostics on an individual card
without taking the router offline) or out of service (taking the entire router down to run
diagnostics).
•
Environmental monitoring and alarm functions—The environmental monitoring
functions of the MBus system include the following:
— Voltage and temperature monitoring for the router’s installed components
— Fan failure sensing for the card cage fan tray and the power supply fan tray
System Specifications
Table 1-8 lists the physical specifications of the Cisco 12008.
Table 1-9 outlines the electrical specifications of the AC-input power supply; Table 1-10
outlines similar specifications for the DC-input power supply.
Table 1-11 lists the environmental specifications of the Cisco 12008.