Big Switch Shines a Switch Light on Open Source OpenFlow Switching

At the core of the Software Defined Networking (SDN) revolution is the OpenFlow protocol. Enabling OpenFlow on physical switches is something that multiple vendors have been working toward. Enabling OpenFlow on virtual switches is now Switch Lightsomething that Big Switch, a startup led by the creators of OpenFlow, is now pushing forward.

The new Switch Light virtual switch is based on Open Source technology called Indigo, which provides an OpenFlow agent. The idea of having a virtual switch for SDN is not new; the Linux kernel itself includes an open source virtual switch called vSwitch. The Open vSwitch has been part of every Linux distribution since the Linux 3.3 kernel release a year ago.

Andrew Harding, senior director of product marketing at Big Switch, explained to Enterprise Networking Planet that there have been some proprietary patches that VMware’s Nicira division has added on top of the open vSwitch. Open vSwitch was originally contributed to the mainline Linux kernel by Nicira.

“The vSwitch is a good thing and we’re glad you can get a vSwitch in the Linux kernel and we’re glad that Canonical and Red Hat are shipping that by default,” Harding said. “The fact that there is now a proprietary patch, that’s unfortunate.”

He added that Switch Light is not a proprietary vSwitch. Rather it is an open source implementation of OpenFlow that works with the open vSwitch that is already in the Linux kernel.

The Open vSwitch in the Linux kernel does not include the forwarding instructions related to OpenFlow. That’s where Indigo and the new Switch Light technology come into play.


The underlying Indigo project that powers Switch Light is now at a stage of maturity where Big Switch can package it and enhance it as something that can be commercially supported.

Indigo is part of the Big Switch Floodlight OpenFlow controller project that had led to the commercial Big Switch controller announced in November 2012.

Indigo is an OpenFlow agent that includes critical network abstractions for data path and configuration.

“Switch Light is really the packaged and supported offering of Indigo,” Harding explained.

For physical switches, Big Switch is packing Indigo together with other required component to enable a virtual OpenFlow enabled switch on Broadcom Silicon. Big Switch is also packaging Indigo in a Switch Light offering specifically for Linux as well.

Switch Light will also help to enable a move up to the latest versions of the OpenFlow protocol. Today many of the switch vendors that support OpenFlow, only support the OpenFlow 1.0 specification. Harding said that Switch Light will support OpenFlow 1.3.x and be backward compatible with legacy versions.


Sean Michael Kerner is a senior editor at, the news service of the IT Business Edge Network,  the network for technology professionals Follow him on Twitter @TechJournalist.

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