Bandwidth provisioning is used to dimension links so that a desired performance is met within a network (e.g. QoS metrics). Practical approaches for the estimation of bandwidth needs rely on rough traffic measurements overlooking traffic fluctuations that may have a negative impact on the network performance. On the other hand, effective theoretical solutions for estimating bandwidth needs require traffic measurements at very small timescales, which limit their applicability due to, for example, transmission rates. This paper describes our research goal of proposing a reliable and scalable solution for estimating bandwidth requirements by means of flow-level traffic measurements, as well as our proposed approach to achieve it. This research, currently in its initial phase, is planned to result in a Ph.D. thesis at the end of four years.