Dynamics of Two Antiparallel TCP Connections on an Asymmetric Link

Data Pendulum designates the packet backlog switch from one side of a bottleneck link to the other in presence of two antiparallel TCP connections. This paper completes the explanation of the Data Pendulum dynamics by elucidating on which side the backlog grows, while identifying the relevant parameters in the process. We also explain why and when the data backlog may switch sides without any packet loss.

We propose a model for the dynamics of antiparallel TCP connections that effectively explains the throughput observed in real conditions. Moreover, the model is applicable to a more realistic case in which buffers are dimensioned in packets rather than bytes, the case that previous models could not capture.