This read-write INTEGER is the filter identifier an NMS sets to request deletion of a specific filter; the ES/1 deletes the matching filterEntry, resets this field to zero, and updates the filter count and table afterward. An admin uses this to remove an obsolete or misconfigured traffic filter without having to touch the underlying filterTable rows directly. Setting filterDeleteID to the ID of a filter that's no longer needed triggers the device to remove that specific filterEntry automatically.