juniFileXferIndex is a read-only integer (1-65535) that uniquely identifies one entry in the juniFileXferTable, the row used to key a specific file-transfer job. Because the table can hold multiple concurrent or queued transfer entries, an admin or management station uses this index to reference a particular transfer's other objects, such as its status, direction, and filenames, via SNMP. For example, an NMS creating a new transfer might pick an unused index like 3 and then address that entry's status as juniFileXferStatus.3.