Retransmission percentage is the total number of TCP segments retransmitted, divided by the total number of TCP segments sent. TCP segments are retransmitted when their receipt is not acknowledged by the destination host. Excessive retransmissions waste network resources, degrade network performance, and effect user response times. See the IBM z/OS Communications Server IP Diagnosis Guide for assistance in isolating the cause of the retransmissions and take corrective action.
By default, this situation starts automatically.