Technological advances and the growing migration of applications to the cloud are forcing corporations to rethink the way they conceive and build wide area networks (WANs). Since the early 2000’s, organizations have transitioned from the highly scalable WAN technology called Frame Relay to multi-protocol label switching (MPLS) networks that carry video and voice traffic.
But MPLS networks are not architected for the new traffic patterns and the security and performance expectations engendered by the adoption of cloud services. Now, a lot more traffic in the WAN move from the branch or from the data center (DC) to the cloud, rather than from DC to DC, or branch to DC.
Organizations are also frustrated by their carriers’ sluggishness in responding to changing WAN needs – especially as cloud apps drive greater traffic to MPLS – and by the high cost of MPLS bandwidth compared to broadband internet connectivity.
IT leaders and influencers from multiple industry sectors shared these and other WAN concerns at a recent IT leaders' gathering hosted by Silver Peak, a Silicon Valley-based company bringing innovation and automation to the WAN, and Network World Asia.
Recognizing that a better WAN is needed to address their concerns, participants weighed in on the possibilities offered by software-defined WAN (SD-WAN), especially in fulfilling business transformation and cloud-first objectives.
“SD-WAN does not replace MPLS or the internet,” said David Hughes, founder and CEO of Silver Peak. “SD-WAN [corresponds to] the hypervisor and orchestration layer in the software-defined data center. It lets you run any app on any network, define your business intent [for the WAN] and translate that directly into how the network runs.”
The participants’ priorities for the WAN include maintaining consistent and optimized network performance for delivery of applications such as voice, video or VDI wherever they reside; ensuring secure, quick and easy access to data and high-quality communication links between headquarters and remote offices; and augmenting or replacing MPLS with broadband internet to seek bigger and better bandwidth at significantly lower cost.
Hence, a better WAN entails more than just building the SD-WAN. Organizations have to think about performance, security, visibility and extensibility.
“Enterprises care about consistency of performance, about SLAs, and about quality of service (QoS), [even] on the internet” Hughes said. “The second thing is around security.” Many vendors typically leverage IPSec virtual private network (VPN) connections using edge-to-edge AES-256 encryption to secure data in-flight across the SD-WAN fabric.
“We encrypt the traffic regardless of whether it’s going over the internet or over MPLS,” Hughes said. “Although that adds a tiny bit of IPSec overhead, the data is always encrypted.”
Apart from security, extensibility is crucial because “it’s one thing to talk about SD-WAN as a greenfield thing where you go in, rip out a thousand branches overnight and have a brand new SD-WAN,” Hughes said. “But most people want to look at how to do that in stages.”
A good first step toward SD-WAN is to adopt the hybrid approach, using MPLS for the QoS, and turning to broadband internet if the MPLS network is not performing as well.
“About 75% of our SD-WAN deployments are hybrid,” Hughes added. “The customers using MPLS are capping or containing their MPLS spend and then adding internet. That gives them roughly 50% savings in terms of bandwidth costs. The other 25% of our customers are getting rid of MPLS and in that case, they realize, depending on the region of the world, something like 90% savings.”
Silver Peak also enables customers to fully adopt broadband internet by relying on the power of error correction to reconstitute dropped packets or reassemble out-of-sequence packets from multiple paths across the network.
For example, two diverse internet services can be used at the same time. “Depending on the type of QoS and the types of traffic, we can have higher or lower error correcting overhead,” explained Hughes. “That lets us correct for missing packets and deliver what is effectively synthetic QoS over a set of internet services that we don’t control.”
Organizations can also create multiple logical overlays from two or more diverse physical WAN connections. If a WAN link fails or if an outage or brownout occurs, the SD-WAN service automatically switches over to a remaining or a secondary connection in less than a second. “You can have a link or [all] links go to brownout but still have private line-like performance running over the top,” Hughes said.
The road ahead
Hughes also suggested that organizations need both visibility into the type of apps being used on the network for decisions on how to route and handle traffic, and network visibility for debugging.
Silver Peak measures loss, latency and jitter using the sequence number and time stamp on every packet flowing through every path. In addition, it can tell which hop on the path the loss or latency is introduced.
This is where artificial intelligence inspires Hughes’ vision of a self-driving WAN. Silver Peak collects copious amounts of network measurements and turn them into actionable data. Put simply, it helps network teams to quickly either pinpoint a problem in the WAN or affirm the problem lies elsewhere, such as in the LAN.
With more than 350 customers having deployed its EdgeConnect solution as the basis for an SD-WAN along with 2,000-odd customers using its broadband and hybrid WAN solution, Silver Peak shared several successful case studies during the discussion.
The company is anticipating another 150 to 200 SD-WAN customers this quarter. “In Asia Pacific, problems like indirect routing, bringing things back to a hub and then back out, or access services being located far away from users, are bigger than in America and [create a ready need for SD-WAN and internet broadband].”
Silver Peak’s partners are certified to deliver professional services and deploy its offerings for customers. Still, organizations have to consider the skill sets required in-house to support their SD-WAN initiatives.
“In the initial phase of SD-WAN implementation, you’ll still need the same kind of people that [you have today],” said Hughes. In the future, he expects a shift away from detailed certifications and knowledge of arcane capabilities toward a greater focus on business objectives while tapping opportunities for savings, retraining or redirection of resources.
Considering its fundamental characteristics like zero-touch deployment, automation and the ability to choose multiple paths, SD-WAN certainly lays a strong foundation for next-generation WAN.