Filter
Top Products
Terminology and Concepts
893-01006-C
1-39
Circuit Redundancy and Load Balancing
You can create redundant connections between CLC Circuit Saver or CLC Turbo
virtual ports by defining a secondary mesh of PVCs or PVPs. For each destination
end point of the primary PVC or PVP, the alternate path would ideally take a
different physical connectivity path. You assign a cost, or administrative weight,
to the secondary path. A lower cost signals higher priority. The lower cost path is
used exclusively under normal operations. If the primary and secondary path costs
are equal, traffic will be load balanced by destination MAC address across both
paths. Circuit redundancy offers the quickest possible recovery while localizing
the network disruption.
Redundant MCP
When enabled, the redundant MCP feature allows you to install and configure a
primary and secondary (backup) ATM MCP in the same chassis. This feature is
supported for ATM MCP switch modules in the Centillion 50/100 and the Model
5000BH chassis.
When using redundant MCP, the ATM MCPs must be in the first and second slots
in the chassis; slot numbers depend upon the chassis type. For the Centillion 50/
100 chassis, the MCPs must be in slots 1 and 2; in the Model 5000BH chassis, the
MCPs must be in slots 2 and 3 for the left side or 8 and 9 for the right side. While
in standby mode, the secondary MCP acts as a switching module with all ports
available.
When both MCPs are installed, the switch uses four criteria to determine which
MCP is the primary and which is the secondary. The criteria in order of
importance are: priority, amount of memory, image version, and slot number.
Primary and secondary MCPs monitor each other to ensure mutual existence. If
the secondary MCP detects five failed attempts to reach the primary, it will reset
the switch and come up as the primary MCP, while the previous primary becomes
a switching module. The failed MCP must then be swapped out to restore the
backup protection.
Note:
The redundant MCP should be identical to the primary MCP. It must
have the same switch software version loaded and have the same amount of
RAM.