An adaptive UDT congestion control method with reflecting of the network status

Nowadays, most of networks support several tens of Gb/s with advance of the optical technologies. However, TCP protocol is known to be less suitable for fast transmission due to its AIMD characteristic. As an alternative, UDT protocol has been invented to efficiently utilize network bandwidth; it periodically controls the sending rate for the fixed sync-interval, 0.01 sec. Here, if the network status varies quickly, the available bandwidth is not able to be properly utilized in-between the sync-intervals. In this paper, we propose an adaptive congestion control method in order to reflect the network status. The network status is estimated based on RTT variances. It is divided into four classes, and then properly utilized to differentiate the sending rate. The simulation results show that the proposed method improves the message delivery throughput as well as stability than that of the UDT protocol.