Interconnection of Cabinets (ICIF)
Multiple Point System cabinets can be managed by a single Base Management Module if the Inter-Cabinet Interface (ICIF) ports of the Management Modules (labeled IN/OUT) in all of the cabinets are connected with straight-through RJ-45 cables.
It is recommended that Management Modules be placed in the leftmost slot of each cabinet, and that a single set of Inter-Cabinet Interface cables be used to connect them. It is not possible to have redundant paths between the cabinets. If multiple Management Modules are present in a cabinet, only one ICIF is enabled. If there are any Base Management Modules present, it is the leftmost of them. Otherwise, it is the leftmost Expansion Management Module. The IN and OUT ports are identical to each other.
Also note that it is necessary for the system to select a single Management Module that is permitted to write configuration changes to the cabinet’s hardware, so that multiple Management Modules don’t all try to do it at once. Though it has nothing to do with inter-cabinet messaging, the ICIF performs this function.