Design of General SDN Controller System Framework for Multi-domain Heterogeneous Networks

The integration of two technologies, Cloud Computing and Software Defined Network (SDN) has placed cooperative orchestration between cloud and network into the focus of attention. However, with the continuous expansion of network scale, the data center would inevitably accommodate multiple SDN network devices which are produced from various manufacturers, and even these devices are associated with different SDN technologies. Therefore, application scenario with multi-domain heterogeneous SDN networks occurs. The interoperability and orchestration of cross-domain services, as well as unified management of devices from multiple domains, have become a challenge. At present, except for OpenFlow, the mainstream technologies for SDN implementation include segment routing technology based on MPLS (SR-MPLS) and that based on IPv6 (SRv6). This paper proposes a general SDN controller system framework. This framework is able to shield the discrepancies, which is caused by different SDN technologies, between northbound interfaces of SDN controllers from multiple manufacturers. Besides, it supports unified management of network resources to solve the difficulties of orchestration of cross-domain service in SDN network. Furthermore, this system framework follows the design principles of high cohesion and low coupling, and regard every adapter that manages one SDN domain with specific technology as one sub-module in the whole adapter module, hence with flexible expansion.