OpenFlow could disrupt the networking world in a big way


The last time I looked at OpenFlow it didn't seem that interesting. There were no networking platforms that supported it and I didn't get why they were bothering. My company was presenting at the GigaOM structure event so  I thought I should have a look at what they are saying and came across a panel on network virtualisation and OpenFlow

A light bulb went off in my head; nothing much has changed in the networking space in over 10 years since MPLS was rolled out. Incremental speed updates but nothing that was as game changing as virtualisation. Virtualisation radically changed compute space and then to the storage space in a very short period of time.

OpenFlow enables you to detach the application from the switch or router, just like the hypervisor did for compute. OpenFlow is just an API to the inner workings of the switch, it's not fancy but the applications it enables are. Add a virtualisation layer on top and you enable the kind of innovation that has been lacking in the networking space. Detach the control plane and centralise it and you enable a whole datacentre view across multiple vendors.

One idea that also stuck in my head from the video is the idea of deploy once, use in many different ways. When you build an infrastructure wouldn’t it be great to build it once and not have to change anything physically when a use case or technology changes? SPB (Shortest Path Bridging) is one such example.

SPB (Shortest Path Bridging) will change the datacentre by getting rid of out-dated and misunderstood concepts such as spanning tree. It will allow flat architectures to be built, no more core, distribution and access layers. The network will be a layer 2 mesh. This mas many benefits; faster point to point transfer, faster convergence after failure and better use of available links to name a few. Having to upgrade all the current switches to support this functionality is a major issue. Each switch has to either to upgraded to newer firmware that supports it, a new line card needs to be added or even the whole chassis needs to be replaced. It the control plane was just software on an appliance, only one application needs to be updated. Because the control plane and data plane are separated the control plane can be changed without any impact to the traffic.

I will be keeping an eagle eye on OpenFlow in the coming months. It will take a little while to gain traction but as more vendors get on board and commodity switches get released that have the same or better performance at a much lower price point people will start to take notice.

With the advent of commodity networking silicon I think we are going to see an explosion of Chinese and Taiwanese switches that you can load up an open source or proprietary image for control. Big networking vendors must either innovate or see a big reduction in revenue.