This paper presents a novel resource provisioning method for Virtual Private Networks. TYunk and hose models are well known bandwidth provisioning models for VPNs but both have significant disadvantages if applied to large scale networks. The management complexity of the trunk model highly increases with the size of the network, while bandwidth efficiency of the hose model is often excessively low. We propose an intermediate solution between hose and trunk models. By dividing the network into clusters and using cluster based traffic description we can find an appropriate equilibrium between management complexity and overprovisioning. A method for computing the necessary links capacities for a traffic given by cluster based description is also presented, which makes it possible to design congestion free networks. We also suggest routing strategies to further improve the performance of the new provisioning method. The applicability and limitations of the method and the effect of different routing strategies and fault tolerance are examined by simulating several test scenarios.