Making MPLS VPNs manageable through the adoption of SDN

Virtual Private Networks (VPNs) implemented by Multi Protocol Label Switching (MPLS) tunnels appear in the service offer of many Internet Service Providers (ISPs). Due to the number of technologies that they involve and to the intricacy of their interactions, provisioning, setup, and maintenance of VPNs is a cumbersome task, whose complexity is usually mitigated by using advanced network management systems. We cut these difficulties at their roots by taking advantage of Software Defined Networking (SDN). We showcase the design and a prototype implementation of an SDN controller that, starting from a centralized specification of VPN settings expressed in a high-level simple and flexible language, automatically fills flow tables to implement the requested VPNs. Our implementation of VPNs with SDN promptly reacts to network dynamics (e.g., newly appeared links) and simplifies management a lot by dropping many unneeded technologies.