In this presentation, networking expert and Packet Pushers co-founder Ethan Banks reviews the ins and outs of network virtualization and SDN. Banks says network virtualization is similar to server virtualization in that hardware is abstracted by the hypervisor. The end goal of network virtualization is to have a virtualized network that is decoupled from the physical infrastructure, while still managing hardware as a whole through a virtualization platform.
The concept of network virtualization has been around for a while, but it's been largely focused on specific network devices or small portions of the network. With new network virtualization technologies, it is important to look at the network as a whole, not at devices individually.
Banks covers security in his presentation as well, saying that network virtualization technologies allow users to secure separate network tenants. In fact, modern network virtualization is intended to provide security, and when a company runs a virtualized network, it can still separate departments, maintain testing environments, etc.
To achieve network virtualization, a number of vendors use SDN controllers, which have the power to prioritize traffic delivery based on the specific needs of applications.
Overlays are another popular way of creating virtual networks, and they come in handy when a company is creating a network virtualization container to keep lines of separation between different customers. Banks explains how an overlay is often given a tag, and everyone with the same tag belongs to the same virtual network. There are a myriad of overlay techniques, but at the end of the day, an overlay is essentially a tunnel, he says.