IEEE Project Abstract

Nowadays, there is a fast-paced shift from legacy telecommunication systems to novel software-defined network(SDN) architectures that can support on-the-fly network reconfiguration, therefore, empowering advanced traffic engineering mechanisms. Despite this momentum, migration to SDN cannot be realized at once especially in high-end networks of Internet service providers (ISPs). It is expected that ISPs will gradually upgrade their networks to SDN over a period thats pans several years. In this paper, we study the SDN upgradingproblem in an ISP network: which nodes to upgrade and when we consider a general model that captures different migration costs and network topologies, and two plausible ISP objectives: 1) the maximization of the traffic that traverses at least one SDN node,and 2) the maximization of the number of dynamically selectable routing paths enabled by SDN nodes. We leverage the theory of submodular and super modular functions to devise algorithms with provable approximation ratios for each objective. Using real world network topologies and traffic matrices, we evaluate the performance of our algorithms and show up to 54% gains overstate-of-the-art methods. Moreover, we describe the interplay between the two objectives; maximizing one may cause a factorof 2 loss to the other. We also study the dual upgrading problem,i.e., minimizing the upgrading cost for the ISP while ensuring specific performance goals. Our analysis shows that our proposed algorithm can achieve up to 2.5 times lower cost to ensure performance goals over state-of-the-art methods.