As 2015 fades to black, SDxCentral reached out to a few analysts to find out what their biggest surprises and disappointments were this year in the SDxCentral universe.

So pull up a chair next to the fireplace, pour your favorite beverage, and hit Babs Streisand’s "The Way We Were" on your playlist. The themes will become self-evident. (We’re writing about the year’s biggest M&A deals in a separate story.)

Surprise — The rapid liftoff of SD-WAN. Many vendors are all-in with SD-WAN, ranging from venture-funded startups such as CloudGenix, Viptela, and VeloCloud, to established incumbents and players in between like Talari and Silver Peak. There has been a ton of hype and buzz in the industry and no shortage of PowerPoints and marketecture.

What makes SD-WAN the most interesting is that there is real-world adoption beyond the hype. We are seeing real-world deployments in the mainstream for organizations with large numbers of distributed branches. So this is not like the SDN hype in the data center a few years ago, as real adoption is occurring and quickly. The capital and operational savings are pretty staggering, so SD-WAN resonates with the mainstream. In essence, it has become a land-grab for vendors, and the market is moving fast.

Disappointment — By far, the biggest disappointment is the lack of an SDN application ecosystem. These are the applications that sit on top of an SDN controller and can consequently exert programmatic control over a network infrastructure. First of all, there are only a handful of true SDN applications out there.

Secondly, most of the applications are not portable across different vendor solutions. This is counter to the premise of SDN, which is open portable solutions that foster innovation. We haven’t seen anything remotely close to that. So overall, the focus today for SDN is agility, management, and cost. These are good things, but you don’t need SDN to get them. The real long-term value of SDN is innovation, freedom from vendor lock-in, and bringing applications closer to the network, and we did not move closer to that in 2015.

Surprise — The acquisition of Broadcom by Avago, which already owns LSI and Emulex. It was one of the largest deals of the year that affects the low layers of the networking industry. Since the deal is one technology company purchasing another, it is different from a private-equity deal, but there are similar financial motivations for this. In general, it was seen as a "rollup" transaction as part of the overall industry consolidation, since it now costs more to develop new semiconductors. Since Broadcom is a key merchant silicon supplier that has driven changes in recent years, I hope it will be able to continue with innovation to benefit the entire industry.

Disappointment — The relatively slow adoption of SDN in the broader market, although we have seen good interest in specific use-cases such as SD-WAN. Although there has been a relatively slow uptake of data-center SDN, there is a gradual but steady increase in use. It just hasn't been a rapid sea change that some enthusiastic observers had expected. I think that as end-users start to see its value and existing systems are due for an upgrade, it will gain more momentum in 2016 and beyond.

Surprise — In my area of focus, data center networking, I think one of the big surprises of 2015 was how quickly 25-Gb/s Ethernet happened. The initial multisource agreement (MSA) was only formed in July 2014. Yet by the end of 2015, multiple vendors will already have shipped products – for both server adapters and data-center switches. A couple of the very large hyperscale cloud service providers were amongst the initial drivers of 25-Gb/s, and it is another example of the growing influence that these hyperscale customers exert on the data-center networking market and vendors' product directions.

Surprises — We hit Round 1 of M&A in SDN. I’m talking about Connectem, Pertino, and ConteXtream. Some of them were weak and needed to be bought, and some were strong and got bought. It was sort of the first wave of what I expect to be further acquisitions that we’re going to see.

In SDN terms, 2015 was the year of SD-WAN. There were tons of suppliers, tons of announcements, and good adoption of SD-WAN this year. There were a lot of small deployments and some good-sized deployments across a wide range of different suppliers.

Disappointments — SDN is still in its infancy in the data center. By that I mean in the private cloud, and I don’t mean companies like Google. So if you’re not a leading-edge service provider that’s building its own data center, SDN in the enterprise data center has been pretty weak. You also have to deploy a wide range of DevOps, server, and security folks in addition to networking. It’s hard to get everyone on the same page. There’s a lack of standards, other than Cisco and VMware, and there’s no clear path there.

My other disappoint is standards. Everyone wants to take shots at the standards movement, but I think the standards movement has done SDN an incredible disservice. They’re all trying to position themselves, and it gets all political. I understand that there are significant challenges in standards bodies, but it’s worse when there are seven or eight of them, including the NFV ones.