Congestion Control Mechanisms of Transport Protocols

Existing network transport protocols such as TCP and UDP have limitations when fitting into new technologies, includes, e.g., increased heterogeneity and mobility. In order to solve this problem, our attempt is to design a selfadaptive transport protocol, which can fit into the network condition dynamically according to the parameters given by upper layer and the network layer. This paper analyzes the congestion control mechanisms of nowadays transmission protocols, and does comparison among them in many different aspect. I first describe the congestion control mechanism of traditional TCP, and then give out an overview and list the congestion function of nowadays transport protocols (such as TCP, UDP, DCCP, SCTP, CUBIC-TCP and CTCP). In the end, I do a simple comparison among all the protocols above, and point out the possible advantages and limitations of these protocols under different transport performances (RTT Fairness, TCP Fairness, Utilization Ratio, Packet Loss Rate, Smoothness of throughput, Convergence Time, etc.), Future work will focus on applying our theoretical assumption into experimentation. We will decide the selfadaptive parameters of the protocol as well as further performance optimizations.