This object is the number of unordered data chunks received on this specific association. Unexpected growth here on a single association, when the rest of the traffic is ordered as expected, points to that one specific peer sending data via an unordered stream, worth checking whether that reflects an intentional secondary application sharing the association. An association showing thousands of unordered chunks where sibling associations show none suggests that particular peer's implementation is using unordered delivery for something the others are not.