Abstract:With the evolvement of the Internet, the number of users and applications using Internet increases very quickly. Congestion has become an important issue. To keep the stability of the whole network, congestion control algorithms have been extensively studied. There are two primary components in congestion control. One is the source algorithm executed by host computers and edge devices, the other is the link algorithm executed by network devices. In this paper, the basic concepts of congestion control algorithm,and the research no source algorithm and link algorithm of end-to-end congestion control is summarized.Further research problems in this area are also discussed.