A Case for Overlays in DCN Virtualization

Server virtualization has brought about tremendous value to a modern computing landscape and in particular to data center and cloud infrastructures. Virtual server deployments have become ubiquitous in many development and production sites, in cloud infrastructures and in disaster recovery solutions. Network connectivity is a vital aspect of modern computing. In this work we explore the new requirements the server virtualization brings to the networking world and show how these requirements are different from those of a physical server connectivity. We then describe the Distributed Overlay Virtual Ethernet (DOVE) network architecture for building virtual networks infrastructure. We show how host-based overlays answer the novel networking requirements and describe a working example of their usage for network virtualization. We discuss the benefits and the drawbacks of the method, outline options for its efficient implementation, and show what additional work is required in order to base DCN virtualization on overlays.