Network virtualiSation eXplained

Evolution takes place everyday, but sometimes revolution is needed to kick it up to the next level. And that’s what’s happening in the network world at the moment. Those living in the “old world” will deny that a shift is currently happening and will just tell you it’s just an evolution, but what currently is happening in the network world is a revolution that will create a paradigm shift in the way we will think about network (virtualization). 

But where do we stand today. What is the current status of networks within the enterprise: Welcome to the world networking 1.0!


The intelligence of the network, the software of network components, is always coupled to the hardware that it is running on. In most enterprise environments the network intelligence is governed through a central management tool that will make sure that all devices can be managed from one central location. But this still results in the fact that you need to manage and configure all entities individually to create the desired network layout. The network design more or less is embedded into these networking devices. If it be switching (sw), routing (rt), firewalling (fw) or load balancing (lb); it all needs to be managed and configured individually and all has its own hardware that it runs on. From a flexibility and scalability perspective, this has always been a challenge. It always results in the need for more hardware if you want to achieve the required expansion to deliver the business needs. 

So that’s what we’ve been doing over the last decades. Trying to evolve a system that is limited by nature. Software and hardware tidily coupled, creating monolithic building block that is inflexible by the fact that it needs to be configured and managed individually on a per device basis. 

The key for creating flexibility and agility is in the fact that you want to decouple the software and the hardware. That’s the basic definition of what we call virtualization. Virtualization is a common word within IT today. But in general it’s used for server virtualization. Here compute power (processing and memory) is abstracted from the server hardware that has become commodity and is now used within server virtualization to create one big pool or processing and memory resources. 

Same needs to be done with the network resources. Hardware network devices need to become commodity and network resources need to be abstracted from the hardware layer. To do this network devices need to do one thing : transport network packets across from point A to B. Nothing more nothing less. That’s what hardware should do and it should be done in the fastest, easiest and most efficient way possible. In other words, the hardware should just become a transport layer within the layout of your virtual world. 

But how about all the intelligence? Intelligence is in the software. Software is the key to flexibility and efficiency. Software is needed to run and create a virtual world to build your network design in. This is where network virtualization layer comes into play. Network virtualization is a piece of software that will create that virtual playground for you and that allows you to build network designs in a virtual world. 

It will abstract the network intelligence from the hardware devices and will make that functionality available in the software layer.This does required tight integration with the virtualization software of compute resources. Please keep in mind that  not the network hardware devices themselves are virtualized. Network virtualization software integrates with the compute virtualization layer and therefor requires a compute virtualization platform such as vSphere, KVM, Xen, etc. This is 
 
But the result is that you no longer need physical hardware to provide switching, firewalling, routing or load balancing functionality in your network design. It can now all be created in your virtual world. The virtual world that also hosts your virtual machine workloads. Look at it as if it were your own personal network Lego world. You just use the building blocks as you please and create you own networks according to your network design specifications, but without having to buy those hardware devices.

Virtually everything is possible. This (r)evolution will set a new course in the world we know as networking. I’m already looking forward to the development  in the next couple of years! 

There are more excellent resources out there that you should read if you wan to catchup on network virtualization: 

http://bradhedlund.com/2013/05/28/what-is-network-virtualization/
http://networkheresy.com/category/network-virtualization/
http://blogs.vmware.com/networkvirtualization/

martijn

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