Introducing Project Floodlight

Contributed by Paul Lappas, Head of Open Source @ Big Switch Networks.

I’m incredibly happy to announce some really exciting things that are happening in open source at Big Switch Networks. Today we announced the launch of a commercial version of Indigo Agent, which is a fully deployable thin switching software platform called Switch Light, and a revamped open source site: In this posting I wanted to explain how we got here and why we are making these changes.


OpenFlowHub launched in January 2012 as a registry to promote OpenFlow projects from all over the world. Some of these projects were contributed by Big Switch, some – like Flowscale and Routeflow – were not. We have extremely strong heritage around OpenFlow here: our founder Guido Appenzeller was one of the inventors along with our CTO, Rob Sherwood. And so it was always important that we support the OpenFlow protocol – hence the name OpenFlowHub.

Floodlight quickly became the leading open SDN controller with 6,000 downloads by August of 2012. If you go onto the Floodlight mailing list today, you’ll see individuals from all around the world answering questions directly on the list. People who we’ve never met before. Most time, much more quickly than our own staff. It’s incredible. We have strangers sending in questions and other strangers helping them. The ability for this global community to support users is incredibly powerful.

And Floodlight has grown to more than just a research project. We’ve compiled a great list of how companies are using the project’s to assist with their SDN product development and get to market faster.

List of orgs using Floodlight and Indigo

Project Floodlight

Over time, two things became clear. The first is that it’s incredibly hard to build a community around projects in which you are not an expert. We had people asking questions and using the projects but, we couldn’t control the resources. And so it was hard for us to help.

Second and perhaps more importantly:  Big Switch expanded our open source offerings significantly. With the launch of our next generation Indigo Agent and LoxiGen, we now have projects that cover the entire 3-tier architecture. We’ve got projects at the application tier: virtual switch, openstack plugin, ACL apps, etc, and of course Floodlight, the leading open source SDN controller.

3-tier architecture

100% Open Source SDN Stack

The Indigo Agent rounds out the offering: no other project in the world offers 100% open source solutions to build SDN – all the way down to the data plane. Big Switch now has the complete SDN stack – and so we wanted to re-position the site to reflect that change in focus. It’s about focusing on build the largest open source SDN community in the world.

Licensing and Partners

I want to talk a bit about licensing for the Indigo Agent. Floodlight is and remains licensed under the permissive Apache version 2 license.

Now, distribution has always been a key goal of our open source strategy. That’s why we are open sourcing our code. And when we started thinking about what we wanted to achieve with Indigo, it became clear that we also had to think about our partners, and potential users. We searched for a license that would help us achieve the following goals:

  • enable partners to create openflow enabled devices so customers can choose from a wide range of options.
  • reduce fragmentation – ensure the core engine of Indigo remains open – which is where compatibility with openflow controllers happens.

Uncontrolled customization leads to incompatible implementations – and that is not good of for the end user. The key consideration was the preservation of the core OpenFlow implementation code. And so we chose a license that requires customization to our own files to be open sourced, but permissive enough to allow partners to extend the platform and keep their extensions closed – if they write the code in a way that doesn’t modify our own files. That license is the EPLv1 and you can read more about it here.

Now, some partners want to do more complex things with Indigo, and integrate with hardware SDKs in a way that violate the EPL. For those partners, we also offer a commercial license to OEMs or ODMs. We’ll give them a flexible license that they can use. In addition, if you are a company with an existing relationship with Broadcom, who wishes to license our Broadcom forwarding driver, we’ll give that to you, as well – we’ll do a 3-way NDA with Broadcom. We’ve done that for a number of partners already.


We are really excited about the future of Project Floodlight. We are just getting started. As always, please send in your comments, feedback and advice to

Thank you!

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