Cisco 12008 Environmental Monitoring Facility
Cisco 12008 Environmental Monitoring Facility
An environmental monitoring facility, called the maintenance bus (MBus), supports a variety of functions essential to router operations. These functions include the following:
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System discovery (enabling the router to identify installed components)
Booting software images
Supporting console traffic, logging functions, and diagnostic functions
Monitoring the operational health of the router and reporting error conditions
The MBus facility in the router is interconnected by means of the backplane to the following components:
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GRP
Line cards
CSCs
SFCs
Power supplies
Each of the components listed here contains an onboard MBus module that incorporates two separate transceivers (A and B). Each transceiver has a separate etch (communication path) through the backplane. Consequently, all the MBus modules in the system are reliably interconnected to each other by means of redundant busses. This redundancy enhances the reliablity of the entire environmental monitoring system.
The MBus module on each component is powered by +5.2 VDC that it receives through the backplane from the power supply. A single MBus firmware image executes on all the MBus modules present in the system.
The master MBus module on the GRP monitors all the alarm conditions detected by the MBus modules in the other components of the system. The master MBus module then determines an appropriate response to the alarm condition.
The MBus modules on installed components perform the following functions:
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