Emerging of the virtual network aka Quantum in Openstack

Since Essex the Quantum has become a core Openstack project that promises to deliver a network as a service in the cloud world that is dominated by the virtual technologies. In practice this should mean that you are able to design and create your own network topology for the VMs you run. Another example is the flexibility of defining virtual interfaces your VM's have and elasticity of configuring what VM's can communicate together.

The virtual network idea is sometimes mentioned together with a Software Defined Network (SDN) concept. Although both technologies promise similar benefits they are not the same. In short the promises they do is an ability to:

• Securely partitioning the network 
• Defining virtual network topologies 
• Automating network provisioning

In this presentation we can see some high as well as low level design slides that present the theory in a more understandable, graphical way: http://www.slideshare.net/danwent/openstack-quantum-intro-os-meetup-32612 .

This document has an excellent slide that shows the power of virtual networks by comparing the end user view with a hardware one: http://qconlondon.com/dl/qcon-london-2012/slides/SalvatoreOrlando_QuantumVirtualNetworksForOpenStackClouds.pdf

Taking a step further this is a list of currently supported plugins for quantum in Essex/Folsom Openstack release. Behind almost every plugin we can see a vendor that is needed to be able to create a salable virtual network infrastructure that supports your VMs: http://wiki.openstack.org/Quantum

• Big Switch Networks Plugin
• Cisco UCS/Nexus Plugin 
• Floodlight OpenFlow Controller Plugin
• Linux Bridge Plugin 
• MidoNet Plugin 
• NEC OpenFlow Plugin 
• Nicira Network Virtualization Platform (NVP) Plugin 
• Open vSwitch Plugin 
• Ryu OpenFlow Controller Plugin