The maximum number of TCP segments (in units of maximum segment size MSS for individual connections) received before an acknowledgment (ACK) is generated. If set to 0 or 1, it means no delayed ACKs, assuming all segments are 1 MSS long.
Note that for remote destinations (not directly connected), the maximum number is fixed to 2, no matter what this parameter is set to. The actual number is dynamically calculated for each connection. The value is the default maximum.
0 to 16
Do not change the value. In some circumstances, when the network traffic becomes very bursty because of the delayed ACK effect, decrease the value. Do not decrease this value below 2.