The call for standards creeps into just about every telecom equipment and service category and the SD-WAN market is no different. However, where SD-WAN stands apart is that it's a feature set, not a piece of hardware, so it's harder to pin down what is and isn't SD-WAN, according to Ovum's Brian Washburn.

For a while there, the SD-WAN market felt a little like a crowd of Elvis impersonators. While they all claimed to be the King -- er, provide SD-WAN -- it wasn't always immediately clear if they truly offered an SD-WAN service or were perhaps WAN optimization companies hiding in glittering bell bottoms.

Figure 1: SD-WAN is All Shook-Up Image courtesy of Pixabay.

Both Washburn and Heavy Reading's Sterling Perrin spoke with Light Reading about how MEF has stepped in to create SD-WAN specifications to provide clarity in the market, and how this service definition could impact the SD-WAN market which raked in revenue of "26% quarter over quarter to reach $359 million in the fourth quarter (Q4) of 2018," according to IHS Markit .

Also, Perrin and Washburn discuss whether the Universal Customer Premises Equipment (uCPE) model of delivering SD-WAN is a growth opportunity for the market, or if the economics don't yet add up.

MEF updates SD-WAN standards
In response to the growing SD-WAN market, MEF has released SD-WAN standards to better define the technology as well as SD-WAN's service characteristics and capabilities. The standards were initially announced last October at MEF '18; MEF issued the final draft of its SD-WAN specifications in May, called "SD-WAN Service Attributes and Services (MEF 70)."

"Enterprises want to know what they're getting, and service providers want to sell more by eliminating confusion," MEF CTO Pascal Menezes told Light Reading's Mitch Wagner.

MEF expects to release the final specification in mid-July, and if it takes hold, Perrin says a uniform definition could be useful in expanding SD-WAN adoption by providing clarity and weeding out vendors that claim to provide SD-WAN but offer services that don't measure up to the industry standard.

"I think the impact will be more going forward than up until today," says Perrin, principal analyst of Optical Networking & Transport for Heavy Reading. "The vendor interoperability portion is probably less compelling, but getting to service specs that define 'what is an SD-WAN service? What are the attributes you need?' does get at reducing the complexity of evaluating and deploying SD-WAN. If it takes, it will be helpful in expanding deployment."

Deep dive into real-world issues and virtualization deployment challenges with industry leaders. Join Light Reading at the annual Network Virtualization & SDN Americas event in Dallas, September 17-19. Register now for this exclusive opportunity to learn from and network with industry experts. Communications service providers get in free!

MEF's definition specifies that an SD-WAN service needs to provide visibility into the application layer, control over the application layer that extends to dynamic path selection, analytics tools to "make sure policies are adhered to," and several other features such as routing, security and WAN optimization, explains Brian Washburn, practice leader of Network Transformation & Cloud for Ovum.

Washburn adds that a clearer definition of the SD-WAN technology and service will be important when enterprises decide to switch SD-WAN platforms, service providers will "want to port customers in as standardized a way as possible. If they need to graduate from one [SD-WAN service] to the other, you're not starting all over again."

If an enterprise changes its mind about which SD-WAN platform is the best fit, having that clearer SD-WAN technology definition could make the transition to a different SD-WAN service "fast and painless with a smooth migration," says Washburn. This will become increasingly important as service providers are expanding the number of SD-WAN flavors they offer to meet different customer demands.

MEF will also be offering certifications for SD-WAN features which could give vendors a leg up during RFPs, explains Washburn. At the end of the day, though, Washburn says some companies may not meet all the feature requirements under MEF's SD-WAN definition, but if an enterprise is satisfied with current services, they'll likely continue to work with that vendor regardless of what certifications they have.

Next page: Hey, uCPE, show me the money!

Hey, uCPE, show me the money!

Another potential growth opportunity for SD-WAN is in the Universal Customer Premises Equipment (uCPE) model of delivering SD-WAN as a VNF on a white box. This approach provides end-users with room to grow -- adding other VNFs such as WAN optimization or security, for example, on a single white box.

However, this model can be expensive for enterprises and the benefits of NFV -- such as the ability to swap licensing from one vendor to another and add or remove functions without dispatching field engineers -- are are a lower priority in the near term for enterprises and require a heavy commitment, says Washburn.

"A lot of enterprises would turn around and say, 'well, I don't have plans to change my infrastructure in the next three years. It's a theoretical benefit but I don't need to swap out my router every three months,'" he explains. "Moving to the cloud and virtualizing has typically meant lower costs, at least up front, but NFV isn't less expensive and in some cases is more expensive. It just hasn't been a high-priority issue for a lot of enterprises."

Enterprises are interested and know the transition to NFV is important in the long run, but they're moving forward slowly, "implementing here and there like in the data center, but they're not ready to go big and replace existing routers," adds Washburn.

The economic issue is one major concern for enterprises, adds Perrin, but there are also issues with openness and standardization since multiple vendor's VNFs reside on one box.

"You're buying a box that does multiple things but if you haven't deployed those multiple things on day one and you're not quite sure what you're going to do, it's cheaper to buy the single-function box," says Perrin. "It's tough for a vendor or service provider to go to their customer and argue to pay more today for potential tomorrow."

While hurdles remain for the success of the uCPE model for delivering SD-WAN, it is a more compelling deployment model for telecom operators offering SD-WAN as a managed service, explains Perrin. This model makes it simpler for telcos and cable companies to deliver new managed services to customers.

Washburn echoes Perrin's assessment: The "great majority of SD-WAN today, even when it's software, is run on bare metal. So they're taking an x-86 box and routing the application up, it's taking direct control of processes in the box and behaves like a piece of hardware. Most customers are ordering SD-WAN in that traditional way."

Enterprises are still grappling with the best approach to SD-WAN, and there's still a learning curve, says Washburn. Maybe an enterprise picks an SD-WAN platform, but it ultimately doesn't meet their requirements, or they've started on a proof of concept with a service provider but "don't know what step two looks like" and aren't sure how to move forward.

"The challenge with SD-WAN comes down to enterprises trying to figure out how to approach the SD-WAN environment … some vendors say 'it's zero-touch provisioning, this practically manages itself, the centralized controller makes it easy to administer,' and don't fully reflect that SD-WAN has a different set of challenges and it's still quite a complicated technology."

Related posts:

— Kelsey Kusterer Ziser, Senior Editor, Light Reading