AIMD

The additive increase/multiplicative-decrease (AIMD) algorithm is a feedback control algorithm and used in TCP Congestion Avoidance. Basically, AIMD represents a linear growth of the congestion window, combined to an exponential reduction when a congestion takes place.The approach taken is to increase the transmission rate (window size), probing for usable bandwidth, until loss occurs. The policy of additive increase basically says to increase the congestion window by 1 MSS (Maximum segment size) every RTT until a loss is detected.When loss is detected, the policy is changed to be one of multiplicative decrease which is to cut the congestion window in half after loss.
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