Description: The number of multiplicative downward congestion window adjustments due to all forms of congestion signals, including Fast Retransmit, Explicit Congestion Notification (ECN), and timeouts. This object summarizes all events that invoke the MD portion of Additive Increase Multiplicative Decrease (AIMD) congestion control, and as such is the best indicator of how a cwnd is being affected by congestion.

Note that retransmission timeouts multiplicatively reduce the window implicitly by setting ssthresh, and SHOULD be included in tcpEStatsPerfCongSignals. In order to minimize spurious congestion indications due to out-of-order segments, tcpEStatsPerfCongSignals SHOULD be incremented in association with the Fast Retransmit algorithm.