A Techno-economic Analysis of Network Migration to Software-Defined Networking

As the Software-Defined Networking (SDN) paradigm gains momentum, every network operator faces the obvious dilemma – when and how to migrate from existing IP routers to SDN-compliant equipments. A single-step complete overhaul of a fully functional network is impractical, while at the same time, the immediate benefits of SDN are obvious. A viable solution is thus a gradual migration over time, where questions of which routers should migrate first, and whether the order of migration makes a difference, can be analyzed from techno-economic and traffic engineering perspective. In this paper, we address these questions from the techno-economic perspective, and establish the importance of migration scheduling. We propose optimization techniques and greedy algorithms to plan an effective migration schedule, based on various techno-economic aspects, such as technological gains in combinations with CapEx limitations. We demonstrate the importance of an effective migration sequence through two relevant network management metrics, namely, number of alternative paths availed by a node on migration, and network capacity savings. Our results suggest that the sequence of migration plays a vital role, especially in the early stages of network migration to SDN.