Nowadays, most leased line service providers use traditional VPN technology to build their own backbone/metropolitan area network. However, it is slow to establish or change a connection with high construction costs. As the size of the network expands and the number of users grows quickly, it turns to be very inefficient for operation and fault management. Based on SDN switch, the SD-DCI solution provides a new, flexible and efficient way to help users greatly reduce construction and operational costs. Centec SDN switch is already deployed in several commercial SD-DCI networks.