SD-WAN Reality Check: Sorting Out the Hype

Touted for benefits such as reduced costs, increased performance, and ease of management, SD-WAN is having a moment in networking. But are the promises by managed service providers (MSPs) too good to be true, and more importantly, what should enterprises know about selecting an SD-WAN solution?

 

Historically, cloud-based apps and Internet traffic had to pass through an MPLS or a private IP network before reaching the branch. SD-WAN offers an alternative. In a hybrid SD-WAN model, each branch office has an Internet connection, reducing the need for private IP or MPLS connections. With SD-WAN, enterprises can be more agile in their network delivery and benefit from real-time intelligent traffic forwarding.

 

While enterprises can configure SD-WAN networks themselves, many have opted for having an MSP do it for them. These managed services often promote enhanced benefits like all-in-one pricing for equipment and services, ability to scale services easily, and optimized network performance. However, these claims might not be as universal and guaranteed as IT decision-makers might think.

 

While SD-WAN appears to be the latest and greatest, it might really just be “the same solution with a different wrapper,” as Cyrus Nooriala, CEO at Cywest Communications, during the 2019 Society of Communications Technology Consultants conference. In 2000, virtual private networks were considered the solution that would "replace your corporate WAN," and providers claimed that it would reduce overall on-prem telecom infrastructure and related expenses and provide a secure way to scale services, Nooriala said. Now, SD-WAN is the technology that will accomplish all this, and more. Nooriala cautioned against the hype surrounding SD-WAN services, saying, “How often are we going to implement the latest solution… and we still talk about many of the same problems” like bandwidth and performance.

 

When an enterprise approaches Cywest, a telecom services provider, with questions about SD-WAN services, the “conversation usually begins with price,” given SD-WAN providers’ claims around major reductions in operating costs, Nooriala said. But, when an “engineer walks in the room [and] starts to ask … quality-of-service questions, the conversation quickly pivots over to hybrid,” he added. In Nooriala’s experience, many companies end up supplementing their existing WAN connections with Internet broadband services “to compensate for the poor performance and lack of SLA guarantees …. from an Internet service provider,” resulting in more IT spending, he said.

 

Cost isn’t the only variable benefit – increased performance and the promise of fewer dropped calls aren’t guaranteed, as Tom Nolle, principal consultant/analyst at CIMI, pointed out in a No Jitter article. "There are a lot of quality-of-service variables on the Internet, and none of these are really subject to SD-WAN control." Similarly, the ability to reduce dropped calls varies based on the network, and while SD-WAN can theoretically recover an individual voice session if the network goes down, the ability to do so really depends on how a provider has implemented its service. In that piece, Nolle explained:

 

“Remember that SD-WAN creates a virtual network ‘above’ the real network connection, usually the Internet. If the SD-WAN keeps track of the status of these overlay connections, it can recover them if they’re lost because of a network failure, but only if an alternative route is available. If the SD-WAN is aware of individual voice sessions, it likely can recover them quickly. If it uses tunnels to carry multiple traffic types, it may or may not ‘see’ a specific voice session problem, so check how your prospective providers of SD-WAN work if this capability is important to you.”

 

Despite managed SD-WAN services not “delivering on all their promises just yet,” enterprises don’t need to hold up on using them, Tim Proctor, telecom consultant with the Delta Consulting Group, told No Jitter. SD-WAN services can provide crucial support for cloud migrations, improve network redundancy, and offer long-term cost-saving benefits, he agreed. So, the question then becomes: How do IT decision-makers decide on a solution?

 

Like any other IT project, Proctor suggests doing “your homework on the [vendors]” by checking online ratings, making reference calls, and consulting subject matter experts before deciding on a service. Part of the homework is understanding the difference in each provider’s services and deciding which is right for the enterprise. “There are no real standards that define what is/is not SD-WAN, so vendors can label their solutions SD-WAN without accountability,” Proctor went on to say. SD-WAN service features also vary greatly from one provider to the next; one provider might emphasize network security, and another might focus on high performance or multicloud networking.

 

There are a couple of other of things to keep in mind during the homework phase, Zeus Kerravala, founder and principal analyst at ZK Research, said. First, SD-WAN services that aren't cloud-managed "will not change the operational model," and SD-WANs need a higher level of integrated security to ensure end-to-end protection. Additionally, end-to-end network visibility for an SD-WAN service is a must, as it allows "network engineers to be proactive and upgrade infrastructure or services before users start calling with problems," said he said. Lastly, an SD-WAN "should be smart enough to recognize which applications are running over the network and then handle them by policy," which allows applications to talk directly to an SD-WAN, he added.

 

Lastly, when it comes to finally deciding on a solution and implementing it, as Proctor recommended, it’s important to “be realistic with your expectations” and understand that “migration to SD-WAN takes time and effort.”