In early 2013, a new collaborative open source project was spearheaded, called OpenDaylight. While originally led by IBM and Cisco, it was subsequently hosted under the Linux Foundation and drew industry-wide support and resources. The OpenDaylight platform provides a common foundation and a robust array of services for SDN environments. The platform follows a controller model that enables the use of OpenFlow, as well as alternative southbound protocols; it was the first open source Controller capable of employing non-OpenFlow proprietary control protocols, which can potentially make it much easier to integrate with modern, heterogeneous multi-vendor networks. Read further to learn more about the current SDN controller landscape.
The first release by OpenDaylight was Hydrogen in February 2014, followed by Helium in September 2014. The Helium release was significant because it marked a change in direction for the platform that has influenced the way subsequent Controllers have been architected. The change was in the service abstraction layer, the part of the Controller platform that sits just above the southbound interfaces, such as OpenFlow, insulating them from the northbound side, where the applications reside.