  BGP/MPLS IP VPN and VPLS services are considered to be widely used in IP/MPLS
networks for connecting customers' remote sites. However, service providers
struggle with many challenges to provide these services. Management complexity,
equipment costs, and last but not least, scalability issues emerging as the
customers increase in number, are just some of these problems. Software-defined
networking (SDN) is an emerging paradigm that can solve aforementioned issues
using a logically centralized controller for network devices. In this paper, we
propose a SDN-based solution called SDxVPN which considerably lowers the
complexity of VPN service definition and management. Our method eliminates
complex and costly device interactions that used to be done through several
control plane protocols and enables customers to determine their service
specifications, define restriction policies and even interconnect with other
customers automatically without operator's intervention. We describe our
prototype implementation of SDxVPN and its scalability evaluations under
several representative scenarios. The results indicate the effectiveness of the
proposed solution for deployment to provide large scale VPN services.
