At the tender age of two years, network function virtualization (NFV) is already making waves. In 2014, the technology began to prove out, and attention turned to the new carrier revenue streams and other business cases that NFV could enable.

For a look back at NFV's biggest developments in 2014, we've gathered a few thoughts from industry experts.

Caroline Chappell, senior analyst for cloud and NFV, Heavy Reading:

NFV ‘arrived’ and established itself as the way forward for operators in 2014. This reflects the wider global trend to build next-generation businesses that use virtualization — and all that it implies — as an accelerant of business processes and an enabler of business agility.

There has been outstanding progress in the telecoms industry’s understanding of NFV in 2014 – especially around how it differs from IT cloud and what new capabilities need to be developed.

There is still a lot of learning and experimentation to do before NFV can bed down into operator organizations, but I’m confident that we’ll see equally big advances in 2015, especially around NFV orchestration and its interplay with operational and business systems. This is key to making NFV work.

Tom Nolle, president and principle analyst, CIMI Corporation:

I think the biggest change in NFV in 2014 happened in the last four months, and it represented a shift in the focus of operators from the "prove it can work" to "prove it has value" mindset. We started the year with everyone trying to validate the processes of VNF creation and deployment. We're ending it with efforts to combine the features of real NFV products into things that can make a business case for deployment.

The biggest thing that impacted NFV in 2014 was the impending completion of the Phase I work of the NFV Industry Specifications Group. This has set the framework for NFV implementation, both in terms of what it's expected to provide and what it won't provide in the near term. That's helping vendors of NFV-related products to align their own differentiation with areas that the standards aren't going to specify, and it's helping the market to innovate around the edges of NFV to generate better business value.

For 2015, I think the big development will be the evolution of business cases into field trials. You can run lab trials to test technology, but you need field trials to test the business case. Operators are working now with vendors to create a combination of NFV elements that can make a business case, and in 2015 they'll be moving some of these transformations into field trials.

James Feger, vice president of network strategy and development, CenturyLink:

NFV has gained momentum in the supplier community, both in terms of VNF availability, as well as the management and operational tooling associated with shifting to the virtual environment.   We believe 2015 will be the continuation of that, as well as the beginning of the shift for services to be “VNF first.” The options for management and functions continue to improve.

NFV is important to us, because we see it as an opportunity to improve the efficiency and delivery of our product and experience.  As we focus on cloud-enabled services over our network infrastructure, enabling the network with virtual functions brings the dynamic experience into the traditional network world.