Abstract: Shared network topologies, such as dragonfly, subject applications to unavoidable inter-job interference arising from congestion on shared network links. Quantifying the impact of congestion is essential for effectively assessing and comparing the application runtimes. We use network performance counter-based metrics for this quantification. We claim and demonstrate that by using a local view of congestion captured through the counters monitored during a given application run, we can accurately determine the run conditions and thereby estimate the impact on the application's performance. We construct a predictive model that is trained using several applications with distinctive communication characteristics run under production system conditions with a 91% accuracy for predicting congestion effects.