This object is the number of datagrams from the upper-layer protocol currently queued waiting to be sent on this specific association. This is a direct backlog indicator for one signaling link: a consistently nonzero queue means the local application is generating messages faster than SCTP can get them onto the wire for that peer, an early symptom of the very congestion the level and threshold objects elsewhere in this MIB are reacting to. A queue depth of 800 messages on an association whose congestion abate and onset thresholds are all under 100 would mean that link is deep into its most severe congestion state.