This object counts chunks received out of sequence order on this specific association. Out-of-order arrivals on one association usually mean multiple network paths from a multihomed peer are delivering packets with different latencies, or that a congested link is reordering traffic; the SCTP stack has to buffer and resequence these, adding processing delay for that link's messages. A rising out-of-order count on the association to a peer reached over two redundant paths with very different latencies would explain occasional delays in that specific link's message delivery despite no chunks actually being lost.