Analysis and experimental demonstration of an optical switching enabled scalable data center network architecture

Abstract

Optical communication technologies are playing more and more important roles in both intra- and inter- data center networks. Particularly, optical switching network architectures for the inter-rack/pod communications in the data centers have drawn remarkable attention in recent years. By exploiting the high-bandwidth nature and flexible resource allocation capability of optical switching technologies, data center networks (DCNs) may be designed to have high scalability and flexibility, as well as lower cost. Under such design principles, OpenScale architecture has been proposed in our previous works. In OpenScale, reconfigurable optical wavelength/timeslot links connecting with server racks form a logical small-world topology with very simple physical wiring. In this paper, we first review the features of OpenScale and then we investigate the outstanding advantages of OpenScale including high scalability, fault tolerance and effective load balancing. Furthermore, taking data center's inter-rack traffic characteristics into consideration, we verify that OpenScale network can suitably match specific traffic patterns and provide better network performance at the cost of introducing a “vicinity-preferred workload allocation” scheme in the control plane. In addition, a prototype testbed is also introduced, and the proof-of-concept demonstrations of OpenScale's key functionalities in both data plane and control plane are conducted.