Scalability analysis of SDN-controlled optical ring MAN with hybrid traffic

The development of software defined networking (SDN) has instigated a growing number of experimental studies which demonstrate the flexibility in network control and management introduced by this technique. Optical networks add new challenges for network designers and operators to successfully dimension and deploy an SDN-based in the optical domain. At present, few performance evaluations and scalability studies that consider the high-bandwidth of the optical domain and the flow characterization from current Internet statistics have been developed. In this paper these parameters are taken as key inputs to study SDN scalability in the optical domain. As a relevant example an optical ring Metropolitan Area Network (MAN) is analyzed with circuit and packet traffic integrated at the wavelength level. The numerical results characterize the limitations in network dimensioning when considering an SDN controller implementation in the presence of different flow mixes. Employing flow aggregation and/or parallel distributed controllers is outlined as potential solution to achieve SDN network scalability.