In this paper, we propose a set of dimensioning rules, which deliver high quality sessionbased services over a Next Generation Network based IP/MPLS transport infrastructure. In particular, we develop a detailed dimensioning methodology for improving a target QoS requirement. The proposed methodology outlines an optimal equipment allocation strategy for a requested capacity. The benefits of operating a network under the paradigm of generous dimensioning, for converged multiservice traffic flows, include target QoS guarantee, scalability, and network resilience. We present and discuss experimental results which illustrate a practical implementation of the proposed dimensioning strategy and its benefits.