Available Bandwidth Estimation Method Adaptive to Network Traffic Load Considering Fairness with UDT Flows

UDT (UDP-based Data Transfer) is a high speed transfer protocol which can utilize available bandwidth in Long Fat pipe Network (LFN) sufficiently. Meanwhile, it can estimate available bandwidth much greater than the actual available bandwidth when network status is congested resulting in fairness problem. UDT estimates MTR (Maximum Transfer Rate) using pair packets on receiver side and calculates available bandwidth with difference of estimated MTR and current transfer rate on sender side. Therefore, MTR is a major concern in order to estimate available bandwidth exactly. In this paper, we propose Congestion Degree (CD) based MTR estimation method reflecting on the current network congestion status. In this context, the congestion degree stands for a relative index of current network congestion, which is calculated with arriving intervals of pair packets. The simulation results showed that, our proposed method can improve the bandwidth utilization fairness problem significantly comparing with the UDT in terms of the number of flows.