Modern datacenters require a network with high cross-section bandwidth, fine-grained security, support for virtualization, and simple management that can scale to hundreds of thousands of hosts at low cost. This thesis first presents the firmware for Rain Man, a novel datacenter network architecture that meets these requirements, and then performs a general scalability study of the design space.

The firmware for Rain Man, a scalable Software-Defined Networking architecture, employs novel algorithms and uses previously unused forwarding hardware. This allows Rain Man to scale at high performance to networks of forty thousand hosts on arbitrary network topologies.

In the general scalability study of the design space of SDN architectures, this thesis identifies three different architectural dimensions common among the networks: source versus hop-by-hop routing, the granularity at which flows are routed, and arbitrary versus restrictive routing and finds that a source-routed, host-pair granularity network with arbitrary routes is the most scalable.