Setting this to save(1) commits the IP card's current PARAM settings to permanent, non-volatile storage. Because many of the IP card's configuration objects presumably take effect immediately in running memory but are not automatically persisted, this explicit save step is what protects those changes from being lost on the next reboot or power cycle, and forgetting to issue it after making changes is a common way configuration silently reverts. An admin who configures several new IP routes and then power-cycles the unit without first setting cdmipSaveConfiguration=1 would find those routes gone after the reboot, since they were never committed to permanent storage.