Survivable control plane establishment with live control service backup and migration in SD-EONs

It is known that software-defined elastic optical networks (SD-EONs) are programmable and application-aware. However, due to the centralized network control and management, SD-EONs are vulnerable to the network failures that can affect control plane operations. In this paper, we study the problem of survivable control plane establishment (SCPE), i.e., the controller placement and related communication planning for control service backup and migration to protect the control plane of an SD-EON against single node failures. We first propose a novel mutual backup model to improve the survivability of the control plane with high protection efficiency. An integer linear programming (ILP) model is then formulated to solve the SCPE problem with the objective to minimize both the number of deployed OpenFlow controllers (OF-Cs) and the average control channel latency. We also propose a time-efficient heuristic and use simulations to verify that it can obtain similar solutions to those of the ILP. On top of the theoretical investigation, we design and implement the system to facilitate live control service backup and migration with SCPE in an SD-EON control plane testbed. Experimental results demonstrate that the proposed scheme works efficiently, and compared with that using a single OF-C, our scheme achieves much shorter average provisioning latency in dynamic provisioning.