Dell'Oro Group is taking a swipe at measuring the network functions virtualization (NFV) market — the first of many iterations, probably, considering the questions surrounding what an "NFV market" will even look like.

"This may very well be a decade-long transition," says analyst Dell'Oro analyst Shin Umeda.

In a report that came out today (a real one, not an April Fool's report), he's forecasting the NFV market will represent $2 billion in equipment sales in 2018. If that sounds lowball, that's OK.

"I don't think the number's going to wow anybody, but we're trying to put a realistic spin on this as opposed to trying to fuel the fire," Umeda says. "That's the feedback we're getting from a lot of people: They don't believe the back-of-the-envelope numbers they've seen so far."

It seems likely that the $2 billion figure will get changed many times as new factors emerge — such as unforeseen NFV uses that are currently (hey guess what) unforeseen. So, Umeda considers this to be a first take on the market size.

If nothing else, the exercise highlighted for Umeda the links that are missing between the NFV concept and a working market. "Implementation is one of the big questions," he says. "What is the path? What are the chickens; what are the eggs?" Along similar lines, it's going to be a while before the financial model solidifies, he says.

It's not even certain which network functions will get the NFV treatment first. Umeda thinks higher-layer functions — things like deep packet inspection — are a good early bet.

So, the $2 billion figure isn't one you should take to the bank. But it's a start.