High Quality Content by WIKIPEDIA articles! TCP-Illinois is a variant of TCP congestion control protocol, developed at the University of Illinois at Urbana-Champaign. It is especially targeted at high-speed, long-distance networks. A sender side modification to the standard TCP congestion control algorithm, it achieves a higher average throughput than the standard TCP, allocates the network resource fairly as the standard TCP, is compatible with the standard TCP, and provides incentives for TCP users to switch.