An improved focal loss for imbalanced network traffic classification

Abstract

With the continued progress of the Internet, network security has become an increasingly significant issue that requires constant attention and research. Network traffic classification is a key technology used to detect and prevent malicious network activity, and it has accordingly received increasing attention and research. However, datasets related to malicious network traffic classification often have imbalanced characteristics. In conventional traffic classification problems with multiple categories, the sample size characteristics of small categories are often overlooked. To address this issue, the focal loss function was proposed, which focuses on small samples by modulating the trade-off between the positive and negative samples through two hyperparameters and . This article uses convolutional neural networks (CNN) to tackle traffic classification problem and explore the optimal values of parameters in this application scenario. Additionally, this work proposed a novel weight allocation formula to replace , which allowed small class traffic to obtain higher accuracy.