What is Network Virtualization?

Network Virtualization is a certified industry buzzword, and, as such, it is easy to write it off as mere hype. However, It is more than just buzz. Network Virtualization presents an opportunity for Data Center Teams to deliver applications and services to our end-users quicker than previously possible. However, just what is Network Virtualization, and how do we achieve it?…

Whenever vGeeks like myself see the word “virtualization” we automatically think in the context of VMware vSphere and deploying as many virtual instances on a single device as possible. However, this is not the same approach for Network Virtualization.

Instead of virtualizing a physical device, Network Virtualization virtualizes the Network Fabric itself, typically employing some overlay technology such as STT or VXLAN to carve up the network into logical segments.

You might be thinking, “Don’t we already have this capability with the VMware VDS, the Cisco Nexus 1000V, etc?” Well, the answer is, “yes…kinda”

While both the VMware VDS and the Cisco Nexus 1000V both support VXLAN, there still needs to be a Controller component that Network Engineers or even Application Developers can interact with to deploy virtual networks at Cloud speed and scale (i.e. programmatically via API).

With VMware vCloud Director, this would be VMware vCloud Networking & Security (vCNS). In an OpenStack context you would use a Controller that is compatible with the OpenStack Network Service (“Neutron”, fka “Quantum”) like Nicira’s (now VMware) NVP, Cisco’s SDN Controller, the standard Neutron Controller itself, or offerings from other SDN companies.  The Controller will deploy policy on software components running locally on the host (VMware vSwitch, Open vSwitch, etc.) so that the hosts know how to properly and securely forward VM traffic.

If your switch vendor has plugins for vCNS or for Neutron, then provisioning of network resources on the physical switch itself, like VLANs, can also be done programmatically.  In essence, it doesn’t matter what the underlying physical network looks like. As long as all required resources are connected properly to a physical switch, you can provision your network effectively and quickly.

The Controller can enable central configuration of all switches (no more millions of PuTTY windows open…most of the time).  Also the Controller is NOT in the data plane.  The Control Plane and Data Plane are effectively decoupled.  So, the traffic doesn’t have to pass through the Controller; each host will know how to forward its own traffic.

With recent Storage Virtualization efforts like EMC’s ViPR to complement Server Virtualization and Network Virtualization, Data Center Teams can look forward to improved efficiencies in deploying and maintaining applications. This leads to driving business success and demonstrating the value of in-house IT as some Enterprises are considering moving more workloads to Public Cloud providers like Amazon.

I’m just getting started with deploying Network Virtualization in the lab, and I’ll be posting more articles about this exciting topic over time.

2 thoughts on “What is Network Virtualization?”

  1. Good intro to NV. You’ve mentioned multiple vendors with different products, which technologies will you be using in your lab and could you include visual diagram on your next posts?

    1. Hello Hassan. Thank you for the feedback. I’ll be starting with the OpenStack Neutron Controller, and then I will branch out into using other solutions as I get access to them.

      Look forward to diagrams in future posts. I know this topic is A LOT easier to understand when the components are properly illustrated.

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