SD-WAN: What Can We Expect in 2019 and Beyond?

WAN Traffic Variety Mandates SD-WAN Deployments 

WAN traffic continues to explode as more and more applications are becoming network centric. Many legacy applications required the data to be located close to the applications, so it was often stored on the local PC, department server or in the company data center. In each of these cases, the WAN was rarely part of the transmission path to get the data from the server to the client and vice versa. Today, data and workloads can reside anywhere, local server, centralized enterprise operated data center or the cloud, and the job of the WAN is to seamlessly connect users to these applications wherever they reside. It’s often said that one size does not fit all and that’s particularly true for the WAN as we move through 2019 with the variety of network-centric applications growing.

One of the benefits of an SD-WAN is that it’s highly agile and can accommodate different application types. For example, from a network perspective, copying a file across the WAN is much different than making a voice call. One requires a lot of bandwidth for a short period of time and the other requires consistent bandwidth. With a file copy, if packets are dropped, no one will notice. With a video call, dropped packets cause executives to call IT and question why they spent money on these high priced cameras and yet nothing works.

If all WAN traffic was equal, architecting a WAN would be easy and an SD-WAN might not be needed. But all WAN traffic will continue to change as new application types are created, making agility a key requirement. The value proposition of SD-WAN was initially centered around the cost savings of moving from private MPLS circuits to broadband internet, but now that’s just a side benefit. Network agility is the real value. Even if an SD-WAN cost more, it would still be worth it because an SD-WAN is able to respond and adapt to changing network conditions to deliver the highest quality of experience to application users.

One of the challenges to designing a WAN is understanding what’s driving traffic growth today.  The recent IHS Markit Enterprise Edge Connectivity Strategies survey sheds a little light on this.  The survey asked respondents to rate factors in the growth of traffic on their WANs on a scale of 1 to 7, where 1 means not a driver and 7 means a strong driver, and the results showed the wide range of applications that rely on the WAN today.

Exhibit 1: Back-up, cloud are the top WAN traffic drivers, perfect for SD-WAN
Exhibit 1: Back-up, cloud are the top WAN traffic drivers, perfect for SD-WAN

SD-WANs are ideally suited for data, voice and cloud

Below are top drivers of WAN growth and how they affect the WAN and how an SD-WAN can help optimize performance.

Data storage and backup is the top response at 52 percent of respondents. This creates some interesting challenges for the WAN as it can send massive amounts of data over the WAN, but timeliness isn’t considered business critical. Whether it takes eight minutes or eight hours to complete doesn’t matter as long as it completes. What often happens is that backups take so long to complete that they interfere with more important applications. With an SD-WAN, backups and storage services can be isolated in their own queue so even if they take hours to complete, workers won’t be impacted. In this case, an SD-WAN with unified WAN optimization can be used to accelerate the performance of data and storage transfers.

Cloud-based services (51 percent).  One could look at “cloud services” and say it’s a very broad category with the applications having nothing in common. That is somewhat correct as Webex is very different than Salesforce or Office 365. However, there is one point of commonality and that’s they’re all hosted in the cloud. With legacy WANs, all cloud apps come in through the central data center internet connection, hop over the WAN, hit the branch and then reverse the cycle creating a ‘trombone’ effect that introduces latency, making it a significant WAN challenge. SD-WANs can be configured with secure local Internet breakout with specialized cloud on-ramp features so branch workers can access them directly, cutting down dramatically on branch to data center traffic. This saves money and increases available bandwidth, but more importantly, dramatically improves application performance.

Voice communications (47 percent). Voice is an interesting network application as a call requires very little bandwidth, but it’s extremely sensitive to latency, packet loss and jitter. Traditional networks did an effective job handling voice traffic, but it required a significant amount of engineering time and capacity planning to keep pace with the growth in voice. With an SD-WAN employing tunnel bonding, real time voice traffic can traverse the WAN in its own virtual overlay using path conditioning to maintain quality of service (QoS), even over consumer-grade broadband.

Access to applications in our data center (46 percent). Contrary to popular belief, not all applications are moving to the cloud. In fact, many applications are still hosted from on-premises data centers where the WAN is used to connect users to workloads and data. SD-WANs won’t handle this traffic much different than a private WAN, but performance should be improved as apps move to the cloud. Also, as the data center to cloud transition continues, an SD-WAN makes it easier to reduce private WAN bandwidth needs and increase the reliance on broadband internet connection ensuring a smooth transition.

The bottom line

WAN traffic is diverse, and we can only expect it to become more varied: collaboration, video, streaming, SaaS, IoT and more. To compound matters performance demands placed on the WAN are increasing as computing is placed at many locations with dynamically shifting workloads. The result is complexity created by this new “traffic soup” and only an SD-WAN, with the automation it brings, can deliver performance at the level required to deliver the highest quality of experience to application users.