Denial-of-Service (DoS) is one of the most important and severe attack in the interconnected systems. In this paper, the authors present a DoS attack detection and mitigation. The detection system that uses Multivariate Correlation Analysis (MCA) for accurate network traffic characterization by extracting the geometrical correlations between network traffic features. Their MCA-based DoS attack detection system employs the principle of anomaly-based detection in attack recognition and the mitigation system uses the IP-trace back algorithm. The effectiveness of their proposed detection system is evaluated using KDD Cup 99 dataset and the influences of both non-normalized data and normalized data on the performance of the proposed detection system are examined.