"These are first cuts at stretching VLANs across an L3 domain," Casado says. "They rely on an existing but not very ubiquitously deployed control mechanism. They don't provide what I would consider full network virtualization. You can't create a 10,000 node VXLAN. You can't arbitrarily support services. There's no model for doing security, policy," etc.
VMware's Sequeira says he expects VXLAN to be "a complete line-speed, hardware assisted-enabled" technology that "completely removes the need (for applications) to worry about what happens underneath in the actual physical infrastructure."
In the meantime, enterprises want to be able to customize their networks but also make them adaptable, something they are finding difficult to do with closed homegrown scripting and vendor-specific attributes for configuration and extensibility.
"Large enterprises are looking at this as a way to get back on the standards track and not be tied to homegrown systems," says HP's Gillai. "Because of the need to have very granular control of policy in their systems, they've built whole worlds of scripted systems to provide that with SDN you'll be able to do in a much more elegant fashion."
And it can't come too soon. IDC says OpenFlow hardware, software and services, starting from a barely detectable base this year, will be a $2 billion market by 2016.
Big Switch is in the middle of the building momentum. In the first quarter of this year, it shipped eight times as many OpenFlow controllers as it did in the fourth quarter of last year. And last year, when less than 10% of the conversations around OpenFlow and SDNs turned into trails, now 70% do.
"We're understaffed for that level of change in the business," Big Switch's Forster says. "The market in January completely turned on us. It was like night and day."
Jim Duffy has been covering technology for over 25 years, 21 at Network World. He also writes The Cisco Connection blog and can be reached on Twitter @Jim_Duffy.
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