OSA: An Optical Switching Architecture for Data Center Networks With Unprecedented Flexibility

A detailed examination of evolving traffic characteristics, operator requirements, and network technology trends suggests a move away from nonblocking interconnects in data center networks (DCNs). As a result, recent efforts have advocated oversubscribed networks with the capability to adapt to traffic requirements on-demand. In this paper, we present the design, implementation, and evaluation of OSA, a novel Optical Switching Architecture for DCNs. Leveraging runtime reconfigurable optical devices, OSA dynamically changes its topology and link capacities, thereby achieving unprecedented flexibility to adapt to dynamic traffic patterns. Extensive analytical simulations using both real and synthetic traffic patterns demonstrate that OSA can deliver high bisection bandwidth (60%-100% of the nonblocking architecture). Implementation and evaluation of a small-scale functional prototype further demonstrate the feasibility of OSA.

I. Introduction

Many online services, such as those offered by Amazon, Google, Facebook, and eBay, are powered by massive data centers hosting hundreds of thousands of servers. The network interconnect of the data center plays a key role in the performance and scalability of these services. As the number of hosted applications and the amount of traffic grow, the industry is looking for larger server-pools, higher bit-rate network interconnects, and smarter workload placement approaches to satisfy the demand. To meet these goals, a careful examination of traffic characteristics, operator requirements, and network technology trends is critical.