The last legacy systems to make the shift to software-defined networking may be network engineers' minds, but even those are changing.
For many enterprises that want to move from traditional hardware-based networks to infrastructure that's defined by software, the most important thing is for the new architecture to look like the old, SDN pioneer Martin Casado said Wednesday at the Open Compute Project Summit in San Jose, California.
Casado, who co-founded Nicira Networks in 2007 and sold it to VMware in 2012, said he used to think hardware would be the toughest thing to change in enterprise networks. It turned out that mindsets and organizational structures are the biggest hurdles, he said.
"Probably the most inflexible things in industry are people's brains," Casado said during a panel discussion on opening up network hardware. SDN might ultimately allow companies to replace traditional switches and routers with open-source hardware, but the engineers and administrators who have been doing things the same way for years will need help to make the transition, he said.
"I do believe it is incumbent on us as a community to create solutions that look like the solutions used to look before," Casado said.
Casado's comments were aimed beyond large, technically ambitious companies such as Microsoft and Goldman Sachs, both of which have already started down the SDN path and were represented on Wednesday's panel. Those kinds of organizations have the engineering teams to blaze SDN trails themselves, but most don't, Casado said. "As you go downmarket, you're going to have to have more tools to help do this," he said.
NSX creates a so-called "overlay" network in software that runs in a hypervisor or in top-of-rack switches in a data center. It provides a virtual way for IT departments to make changes in the network, while the enterprise's physical network can remain in place, according to VMware.
SDN platforms from VMware and other vendors let enterprises move the control point for their networks from physical routers and switches with specialized interfaces to a separate software layer. This opens up networking to programming tools that are familiar to software developers, with the promise that it will become easier to make networks serve applications' needs.
But as SDN changes how networks are managed, both thinking and skill sets have to evolve, panelists said. Enterprises need both savvy developers and people who understand networks.
"The intersection of that is still too small today," said Dave Maltz, partner development manager at Microsoft. "We have a hard time finding people with those intersecting talent sets, but that pool is growing."
"You can often pair great developers with great network engineers," Maltz said.
"Historically, we were hiring a lot of pure network engineers," said Matthew Liste, managing director of core platform engineering at Goldman Sachs. "Now it's a blend of software developers and engineers, and gradually we're finding people who are great network engineers and also great software developers."
"That's a really exciting shift," Liste said. "But it's taking time."