Cisco XR 12406 - Manual (Page 132)

Chapter 4 Troubleshooting the Installation
Identifying Startup Problems
4-2
Cisco XR 12406 Router Installation Guide
OL-13831-01
When you start up the router for the first time, you should observe the startup
sequence. The normal startup sequence is as follows:
• Each card in the system has an MBus module and at least one DC-DC
converter. Each MBus module controls the DC-DC converter for its card. The
MBus module receives direct current voltage directly from the power supplies
through the backplane. When the power supply is powered on, each MBus
module boots from an onboard electrically erasable programmable read-only
memory (EEPROM) device. Each MBus module processor reads a set of
identification pins on the card to the backplane connector. These pins tell the
MBus module processor what kind of card it is mounted on, which determines
how the MBus module will function.
• The clock and scheduler card (CSC), containing the system clock,
immediately powers up.
• The MBus module on the RP monitors the progress of the CSC power up.
When the CSC has powered up, the MBus module on the RP turns on its
DC-DC converter, powering up the RP.
• The RP sends instructions to each line card to power up. Each line card
processor begins to perform its own boot process and notifies the RP when
the boot process is complete through its MBus module.
• The RP sends a command to each switch fabric card to power up. As each
switch fabric card powers up, its progress is monitored by its MBus module
processor. When the power-up process is complete, the switch fabric card
MBus module notifies the RP that the switch fabric card is online.
• As the boot process progresses for each card, the status of the card is shown
on the alphanumeric LED displays. The left display is powered by the DC-DC
converter on the card; the right display is powered by the DC voltage that
powers the MBus module.
By checking the state of the LEDs on the power supplies and the alphanumeric
displays on the RP and line cards, you can determine when and where the system
failed in the startup sequence.