Study of long-range dependence (LRD) properties in real traffic has received an increasing attention in traffic analysis. A wavelet-based tool for the analysis of LRD is presented in this paper together with a semi-parametric estimator of the Hurst parameter. The estimator has been proved to be unbiased under very general conditions and efficient under Gaussian assumptions. Analysis of the Bellcore Ethernet traces as well as of some VBR video traces using the wavelet-based estimator is reported.