Congestion Avoidance and Control

This classic paper describes TCP congestion control and avoidance mechanisms in detail. It specifically stresses the principle of "packet conservation", i.e. input rate should match output rate of network. It addresses three scenarios where packet conservations fails, using techniques such as slow-start, round trip time estimates, and congestion avoidance.

TCP, as described in the paper, assumes the end points are going to behave well and has incentive to keep the network running as smoothly as possible. That is hardly the case in today's Internet. End points can achieve local optimal results, and damage other's quality of service.

TCP slow start sometimes can be too slow for an extremely fast, reliable, dedicated link in environments such as data centers. Modifications are usually made to boost congestion window to kick start the transfer.

This paper is an excellent choice for this class. It explains reasoning behind each optimization in TCP. However, I do want to point out that many of us have read it as part of CS262A.