Serial Composition of Heterogeneous Control Planes

Standardized data-path provision as achieved by OpenFlow enables the integration of network elements from different vendors in the same forwarding plane, with these elements being managed by the same logically centralized control plane. However, there is no clear abstraction that enables the integration of control planes from different vendors into a single virtually centralized controller. Yet, today's software-dened network (SDN) control planes are highly homogeneous and require networks (or slices thereof) to be controlled by the same controller platform. Hence to deploy a new service in a network, an operator needs to acquire and integrate new implementation modules into the existing controller platform. Though some earlier work has considered increasing the flexibility of controllers by allowing dynamic addition and removal of services, all integrated services need to obey specific constraints of the integrating platform