Modeling TCP performance using graph neural networks

TCP throughput and RTT prediction are essential to model TCP behavior and optimize network configurations. Flows adapt their sending rate to network parameters like link capacity or buffer size and interact with parallel flows. Especially the elastic behavior of TCP congestion control can vary, even when only slight changes in the network occur. Thus, existing analytical models for TCP behavior reach their limits due to the number and complexity of different algorithms. Machine learning approaches, in contrast, are often fixed to specific network topologies. This paper presents a TCP bandwidth and RTT prediction approach that can handle different algorithms and topologies. For this, we utilize Gated Graph Neural Networks and simulated network traffic. We evaluate different encodings of the input data into graphs and how network size, number of flows, and TCP algorithms influence prediction accuracy. Additionally, we quantify the impact of different input features on our models. We show that Graph Neural Networks can be used to model TCP behavior. The resulting models can predict RTT with a median relative error of 2.29% and throughput with an error of 13.31%.