What is SD-WAN and how is it affecting data center connectivity?
8 min read
SD-WAN is the overlay of software over the wide area network. It makes hybrid infrastructure deployments easier to manage and therefore more common. It is worth evaluating if SD-WAN’s relative advantages apply to your business needs.
The acronym SD-WAN stands for Software Defined Wide Area Network. As its name suggests, this is an overlay of software on top of a wide area network. With software sitting at the “control plane,” real-time policy updates and routing control can be automated and made more efficient. SD-WAN enables teams to be more agile in directing users to the applications and data they need and it makes hybrid infrastructure deployments more manageable. The growth of the SD-WAN market, described by IDC Vice President Rohit Mehra as “one of the fastest industry transformations we have seen in years” strongly suggests SD-WAN is bringing something new and valuable to the table. Is it just hype, or will this new technology cause major shifts in the business landscape?
At the very least, the rapid growth of SD-WAN is changing how teams set up and manage their data centers. The growth of hybrid IT and hybrid cloud deployments have been transforming the industry in their own right, and SD-WAN plays right into those shifts by giving teams more flexibility to deploy and manage infrastructure on an as-needed basis.
The question of whether SD-WAN is here to stay may be best addressed by explaining its advantages and disadvantages. It’s early yet for SD-WAN, but these perceptions are informing the decisions businesses ultimately make when architecting their IT infrastructure. As more companies shift into hybrid cloud and colocate their infrastructure in third-party data centers, the implementation of software defined network solutions will also undoubtedly grow. With implementation comes data, and we will be watching closely to see if the promises of additional flexibility and decreased costs come to fruition. In the meantime, let’s get back to SD-WAN and what it means for data center deployments.
- Performance – SD-WAN technology creates high-bandwidth, consistent connections (most often through combining commercial internet connections), eliminating backhauled traffic seen in MPLS connections. These can, of course, be combined with MPLS and other connections for an even more robust network. The software basis of the technology makes it easier to efficiently optimize Software as a Service (Saas) and other cloud-based services (Salesforce, anyone?). Speaking of efficiency, this is also greatly improved at the branch office level – considerably more so when said branches are in rural areas or otherwise lacking on-site dedicated high-bandwidth IT infrastructure.
- Reliability – One of the most significant advantages of MPLS connections over regular internet connections is their extremely reliable packet delivery, as opposed to internet uplinks’ tendency to drop packets. SD-WANs solve this issue by using multiple links (sometimes through multiple providers). When a primary link fails or cannot handle the bandwidth load, one or more of the redundant links are utilized. This provides an extremely high level of reliability.
- Security – Because SD-WANs decouple network hardware from a single central control mechanism, the network can be segmented and data encrypted as it moves from one location to another. With this two-pronged approach, traffic is more difficult to breach. If it is breached, the breach can be quarantined and the damage minimized.
- Full Visibility – This relates to network security, allowing administrators to quickly notice any attacks or other unwanted access attempts. It also is advantageous to the general health of the network and its components – malfunction and poorly performing segments are easy to spot and address.
- Cost – Part of the reason SD-WAN technology has been embraced is its one-two combo of creating versatile infrastructure while actually saving organizations money. Minimizing or eliminating expensive routing hardware and instead relying on the cloud for services and connectivity results in savings – savings that increase with the number of branches involved. Further savings come from the usage of internet links, which are far less expensive than the MPLS links used by conventional WANs and do not require being locked into an expensive contract. SD-WANs also promote indirect savings by lending themselves to other cost-effective solutions. For example, utilizing a hybrid cloud (which incorporates both a private cloud and a much cheaper public cloud service) becomes simpler, with the added advantage of more oversight by administrators over the public cloud portion. Many services can be deployed and adjustments performed without the need to have IT personnel on site – resulting in further savings due to decreased staffing costs.
- Flexible Architecture – This may well be a case of saving the best for last – WAN managers are often most over the moon about this particular feature of SD-WANs. As the data is separated from the control plane, this gives the SD-WAN incredible agility. WAN connections can be easily added and removed, as can bandwidth capabilities depending on the amount needed at a particular time.
- No Connection Quality Guarantee – As most SD-WAN services are provisioned over the internet using public links, there is no QoS (Quality of Service) guarantee. Therefore, you may have a large number of available connections for redundancy purposes, but if they happen to all be performing poorly at the same time, there is no recourse. This can be disastrous for those with set Service Level Agreement (SLA) obligations.
- DIY Aspect/Learning Curve – Though many providers offer subscription services with included support, the greatest savings will be seen by managing most of your SD-WAN infrastructure in-house. This requires your IT department to be well versed in the design, implementation, and maintenance of your SD-WAN.
- Mobile User Security Concerns – Unlike conventional WANs, most SD-WANs lack a dedicated client that mobile device based teleworkers can securely connect to. Where this type of security is key, a non-cloud based perimeter may have to be created, fragmenting network elements and reducing efficiency.
How SD-WAN Is Affecting Data Centers
Mainly, SD-WANs biggest effect on data centers is providing them with agile interconnection. With conventional WANs, data center interconnects have traditionally consisted of a primary data center that replicates and sends information to a backup data center, which remains offline until a failure of the primary or a large spike in the bandwidth requirement. Conversely, SD-WANs and other virtualization solutions utilize their shared and dynamically balanced connectivity resources to interconnect multiple data centers.
Rather than the ‘single primary data center and dedicated backup’ model, there can now be a large, dynamic pool of computing resources that act together to provide the most efficient traffic sharing and failsafe operations possible. An added advantage is the potential savings in data center costs. This virtualization approach minimizes and in some cases eliminates the need for a costly (and costly to maintain) primary data center, and opens the door to cost-effective colocation (the usage of equally effective third-party data centers).
SD-WAN makes it easier to manage a hybrid infrastructure deployment, and this has made this kind of deployment ubiquitous. With real-time information flows, network controllers have visibility into all activities based on user, application, geography, and so on. And this real-time information availability in turn lets administrators create workflows to prioritize and direct traffic to the optimal path.
How Has Adoption Grown?
The adoption rate of SD-WANs has been one of the most impressive in the IT community for some time. In 2017, studies estimated that SD-WANs had a 5% share of the WAN market. Last year, a pair of intensive reports were published that predicted a 40.4% compound annual growth rate, which would see the SD-WAN market grow to a staggering $4.5 billion by 2022. Experts predict that more than 25% of users will be using software to manage their WANs by the end of this year.
This uptake is unsurprising due to the many advantages – but in looking at specific scenarios, the SD-WANs’ capabilities really come to light. When one looks at organizations with numerous branches, cost savings can be considerable. One report estimated the cost of a 250-branch conventional WAN over three years to be $1,285,000. For that same period, the cost of an SD-WAN deployment was estimated to be $452,500. In general, organizations can expect an SD-WAN to cost them as much as 2.5 times less than conventional WAN architecture.
SD-WAN – A Network Solution To Look Into
It is clear that SD-WANs are a networking solution that is worth exploring. Though you may find it may not be right for your organization at this time, many customers find themselves discovering a flexible and robust WAN that is extremely cost effective following implementation. As SD-WAN technology advances and more players join the lucrative market, reliability and cost factors will also become more favorable. We consider it prudent to research the direct returns for your organization before implementing a shift to SD-WAN, but now is certainly a good time to look into what software at the control plane can do for your organization in the future.