Hierarchical Provisioning Algorithm for Virtual Private Networks Using the Hose Model

Virtual Private Networks (VPN) provide a secure and reliable communication between customer sites over a shared network. Two models were proposed for the service provisioning in VPNs. The "hose model" for VPNs alleviates the scalability problem of the "pipe model" by reserving bandwidths for aggregate ingress and egress requirements instead of between every pair of VPN endpoints. In this work, VPN endpoints are connected using a tree structure and our algorithm optimizes the total bandwidth reserved on edges of the VPN tree. We introduce a fast and efficient algorithm in finding the shared VPN tree to reduce the total provisioning cost. Our simulation results indicate that the VPN trees constructed by our proposed algorithm reduce bandwidth requirements as compared to previously proposed algorithms while having a much smaller execution time.