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'Best-of-breed' SD-WAN option supersedes big boxes, expert says

When it comes to SD-WAN technology, deployment options vary, largely dependent on business requirements. But a multiple-vendors strategy might be better than all-in-one SD-WAN.

It's a perennial battle in the networking industry: All-in-one versus buying services from various vendors. And as customers look into software-defined WAN technology, they face the familiar conundrum when choosing a suitable SD-WAN option.

In a recent webinar co-hosted with CloudGenix, Jim Metzler, founder and vice president of Ashton, Metzler & Associates, discussed why potential SD-WAN customers should strongly consider choosing functionality from multiple suppliers rather than a single-vendor big box approach.

As with most networking purchasing strategies, however, the final decision should be founded on business requirements, with a clear strategy in place.

The big box SD-WAN option

In any all-in-one approach, a single vendor provides all of the necessary functions for a platform. For SD-WAN, this could include SD-WAN software, security, management and WAN optimization. The result is a holistic platform, in which, arguably, "the whole is greater than the sum of the parts," Metzler said. This means the user has only "one throat to choke and one check to cut," he added.

But with these big box approaches, each function included in the platform is often merely good enough, Metzler said. The user can easily get locked into a single vendor with inadequate functionality. To replace a single function -- like WAN optimization, for example -- the user needs to get rid of the whole platform. And if certain functionality isn't included in the vendor's offering, the user will still need to integrate those features, which often aren't designed to support third parties.

"No matter what you do, you're never going to get it all in that box," Metzler said. "There will still be a need to integrate with functionality that's not in the box."

To users contemplating this all-in-one SD-WAN option, Metzler recommended they ask the vendor where the "magic occurs" in the platform to determine what makes it unique.

Another factor to consider: Most all-in-one SD-WAN architectures are packet-centric, which means the network makes decisions based on bandwidth, latency and packet loss. "There's nothing wrong with that," Metzler said. "But it's just a starting point."

This packet-centric method is insufficient when it comes to ensuring application delivery performance, he added.

Selecting options from various vendors

When combining features from various vendors, IT organizations rely on APIs to stitch together the features they need. Case in point: SD-WAN vendors partnering with security providers for cloud-based security.

This lets users cobble together the best available features and minimizes vendor lock-in, Metzler said. Further, it supports an application-focused architecture, which can better support application performance, security and compliance, he added. But integrating functionalities can be challenging.

We're seeing a broad movement to APIs that can serve as the linchpin of the integration of all this functionality.
Jim Metzlerfounder and vice president, Ashton, Metzler & Associates

"The classic problem with the best-of-breed approach has been integration," Metzler said. "But we're seeing a broad movement to APIs that can serve as the linchpin of the integration of all this functionality."

The key is to find vendors that build their architectures and products on top of APIs, which better supports third-party integration, said Joel Christner, vice president of marketing at CloudGenix.

"In these cases, the integration is done at the API level, which allows the technology partners to share context, state and configuration," Christner said. "This allows the platforms to appropriately extract the data they need to perform their core functions."

Most APIs won't immediately work together, Metzler added. But smart vendors will clearly document their APIs, detailing the function's syntax and including software development kits.

Choosing between the two SD-WAN options

Enterprises must have a clear strategy in place before they make an ultimate decision, Metzler said. They need to understand the problem they're trying to solve before choosing an option -- and it should be focused on a factor other than cost, he added.

"Just about any SD-WAN solution will reduce cost, so choose a vendor if that's the case," Metzler said. But, he added, the more important considerations should center around which SD-WAN deployment option results in the best application performance and security.

If it makes sense to use services from multiple vendors, determine the value each feature might offer the network, and then make sure each supplier has a good API strategy in place that will let you build the SD-WAN platform that best meets your needs.

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