Ronny Lam

about://tech

Do SDN Northbound APIs Need Standards?

SearchNetworking has, again, an article about the standardization of the northbound API for SDN:

Developers want to write useful SDN apps, and they don’t know what to write to. “They just want something popular that will give them good market share,” Pitt says. “Companies making commercial controllers all want their northbound API to be the popular one – but they’ll have to win this one through merit. So far, nobody’s written a controller that everyone naturally gravitates toward.”

So far, we have a standardized OpenFlow protocol, a southbound API from the controller and several controllers, each delivering their own OpenFlow (spot) solution with sometimes a northbound API.

As a company that is writing an application for SDN management I fully understand the problem. Which controller are you writing for? Which controller are your customers using? If you choose one, are you ignoring the others? Or even a step further: are you going to deliver your own controller? This is a problem, and the problem is not very different from the problems we see in traditional networking. Each vendor has its own API/CLI. Standardizing the hardware part is one thing, but now we see this problem moving to the upper layers.

Feature wise I don’t see a possibility of standardizing the northbound API. The solutions applications are trying to deliver are so different from each other that no standard API will hold.