Heavy-Hitter (HH) flows are well-known in the field of networking, mainly due to their resource consumption, which is considerably higher than the majority of flows. Their reliable detection and management are critical to optimising network performance. Nevertheless, to date, there is no generally accepted and widely used methodology for HH threshold selection. Indeed, different works use distinct thresholds without the support of a detailed or systematic study. In this paper, we provide useful insights and suggestions on how to determine more justified and valid thresholds. Based on the obtained results, we conclude that no threshold can be used universally to separate flows into HHs and non-HHs. A threshold that performs efficiently in one network may underperform in another. Threshold and HH definitions are often application-dependent, and therefore, threshold selection should include a detailed analysis of the network and its traffic. We also highlight that TCP and UDP flows should be classified with different thresholds because HHs exhibit different characteristics in such protocols. Lastly, we point out that the use of more than one threshold leads to accuracy and efficacy improvements in HHs classification.

高命中（HH）流在网络领域是众所周知的，主要是因为它们的资源消耗大大高于大多数流。它们可靠的检测和管理对于优化网络性能至关重要。然而，迄今为止，还没有用于HH阈值选择的普遍接受和广泛使用的方法。实际上，在没有详细或系统研究的支持下，不同的作品使用了不同的阈值。在本文中，我们提供了有关如何确定更合理和有效阈值的有用见解和建议。根据获得的结果，我们得出结论，不能普遍使用阈值来将流量分为HH和非HH。在一个网络中有效执行的阈值可能在另一个网络中表现不佳。阈值和HH定义通常取决于应用程序，因此，阈值选择应包括对网络及其流量的详细分析。我们还强调指出，由于HH在此类协议中表现出不同的特征，因此应使用不同的阈值对TCP和UDP流进行分类。最后，我们指出，使用多个阈值可提高HH分类的准确性和功效。