Beta Draft Confidential
Redundancy
Redundancy Manager
CBX 500 Multiservice WAN Switch Hardware Installation Guide
4/5/03
D-5
Redundancy Manager
The Redundancy Manager is a background task that runs on each SP module installed
in the switch. It performs the following functions:
•
Establishes an active and redundant module for each pair of SPs.
•
Monitors the integrity of active modules by means of keep-alive messages over
the cell bus. (For more information, refer to the section,
“Keep-Alive Monitoring”
on page D-6
.)
•
Detects a failure in the active module and instructs the redundant module to
disable the active module and perform a warm boot to become the active module.
•
Monitors the PRAM in redundant modules to ensure identical configurations are
maintained between the active and redundant module. If a mismatch is detected,
the active module automatically updates PRAM on the redundant module.
The Redundancy Manager is distributed and runs on each module in the system.
Redundant modules use a keep-alive mechanism to monitor their active partners. If an
active module fails, the redundant module reboots it and takes over as the active
module. The switchover does not have any direct effect on other modules in the
switch. The modules may, however, not be able to access information on the resetting
module.
During SP switchover, the CBX 500 can establish and reroute circuits, but cannot route
IP traffic through this node (that is, no NMS traffic).
