Where Do We Stand With SDN?

I wrote my first analyst report on SDN back in 2012. Since then there have been more analyst reports, white papers, and blogs written on SDN than I or anybody else could ever count. The sheer volume of documents on SDN can lead networking professionals to become SDN-weary. However, since it is often the case that where there’s smoke there’s fire, that volume of documents leads me to ask: Where are we right now relative to deploying SDN?

SDN GrowthI just published The 2015 Guide to SDN and NFV. In that e-book I highlighted what has changed with SDN over the last year. One thing that has changed is that most of the discussion around whether or not an overlay network virtualization solution — such as VMWare’s NSX — is indeed SDN has gone away. Today, most IT professionals regard an overlay solution as being a form of SDN.

Another change in the SDN landscape over the last year is that in February 2014 the OpenDaylight community issued its first software release, called Hydrogen, and in September 2014 issued its second software release called Helium. A number of vendors have announced their intention to use the OpenDaylight solution as the basis of their SDN controller. This creates the potential for SDN solutions based on OpenDaylight solutions to reach critical mass in the near term, and hence accelerate the adoption of SDN. In a recent conversation that I had with Neela Jacques, the executive director of the OpenDaylight Community, Jacques stated that over the next year that the OpenDaylight community will be working on a number of activities, including improving the stability of the current release and fixing bugs. They are also likely to add network virtualization functionality, federation capability, and possibly develop a policy repository.

Another change that has occurred in the SDN landscape within the last year is that the Open Networking Foundation (ONF) established the Northbound Interface (NBI) working group with the goal of eventually standardizing SDN’s northbound interface. In a conversation I had with Sarwar Raza, the chairman of the working group, he said that standardization was not a short term goal of the group and that “Our goal in the next year is to formalize the framework along with the information and data models and then iterate some with code before we even start a standards discussion.” The NBI working group intends to work with one or more open source initiatives to develop working code for the NBIs that the group aims to put forward for standardization at an appropriate time in the future. Raza explained that the working group has a good relationship with both the OpenStack and the OpenDaylight initiatives but that when dealing with open source initiatives “There is no magic handshake”. What he meant was that none of the open source initiatives are going to agree in advance to produce code for NBIs that are under development. The reason that this initiative interests me is that if we do develop standards for the northbound interface, that will increase the likelihood that application vendors will write applications which can take advantage of the intelligence in the SDN controller, which will in turn likely accelerate the adoption of SDN.

The 2015 Guide to SDN and NFV also contained results of a survey that identified how the 176 survey respondents were approaching SDN. Eleven percent of the survey respondents indicated that they were running SDN somewhere in their production network. While this is not a large percentage, it is a notable increase from the 6 percent of survey respondents who a year ago indicated that they were running SDN somewhere in their production network. The percentage of survey respondents either currently analyzing vendor’s SDN strategies and offerings or who were running SDN in a lab or limited trial also increased somewhat over the last year. Taken together this data indicates a slow, steady adoption of SDN.

So, getting back to the title of this blog: Where do we stand with SDN? One piece of positive news is that there are a number of broad industry initiatives such as the OpenDaylight community creating open source solutions and the ONF’s NBI working group working on standards for the north bound interface that have the potential to accelerate adoption. Another piece of positive news is that while not in large numbers, more IT organizations have currently implemented SDN than had last year, and an increasing number intend to run SDN in their labs or in limited trials. While we are clearly not racing towards broad adoption of SDN we are clearly making the kind of slow, incremental steps that are necessary, given the magnitude of the change brought on by SDN.