Abstract: The performance of TCP over bandwidth asymmetry networks is analyzed.With the definition of normalized bandwidth ratio, the formula to calculate the TCP throughput with asymmetrical bandwidth and infinite reverse buffer is deduced. Effectiveness of deduction is verified by simulation studies. In a network with asymmetry bandwidth, throughput achieved is not only dependent on the traffic and link characteristics of the forward direction, but also significantly determined by those of the backward direction. Through simulations and our deduction, we conclude that the TCP throughput is linear to the reverse bandwidth with infinite reverse buffer and nonlinear to that with finite reverse buffer.

Key words: computer networks, transport control protocol(TCP), bandwidth asymmetry