Description: This table contains all the FC IDs that have recently been released. So it lists all the FC IDs that have valid WWN to FC ID mappings and currently not assigned to any ports. These FC ID were assigned to ports and now, have been released. This cached FC ID contains only Area ID and Port ID information. The FC ID cache is kept to provide best effort re-assignment of same FC IDs. i.e, an Nx_port would get the same FC ID when it asks for a FC ID again, after releasing it.