BIC TCP (Binary Increase Congestion control) is an implementation of TCP with an optimized congestion control algorithm for high speed networks with high latency: so-called "long fat networks".
BIC has a unique congestion window (cwnd) algorithm. This algorithm tries to find the maximum where to keep the window at for a long period of time, by using a binary search algorithm.
BIC TCP is implemented and used by default in Linux kernels 2.6.18 and above. The default implementation was again changed to CUBIC TCP in the 2.6.19 version.