What is SD-WAN… and Why Do You Need It?

A key driver of adoption is the projected cost reductions of SD-WAN compared with a traditional network architecture.

If you’ve heard of software defined networking, you may be ready for SD-WAN. It applies the concept of “software defined” to the wide area network, offering numerous advantages.

No Longer MPLS or Broadband. Now WAN Can Be Both!

SD-WAN aims bring to networking the same agility and flexibility virtualized servers and storage are already known for. That’s a good thing because WAN for branch office integration adds cost and complexity.

Before SD-WAN, multi-site enterprises were on the horns of a dilemma. They could go the expensive route, such as linking remote offices via MPLS. Or they could choose cheaper broadband options without the same functionality. It was nearly impossible to fully integrate both.

Now SD-WAN promises to combine connection types into a highly flexible, lower cost WAN.

SD-WAN Advantages and Cost-Savings

Universal SD-WAN features include:

  • Support for multiple connection types, such as MPLS, DSL, fiber, cable, and LTE
  • The ability to load-share across WAN connections using dynamic path selection
  • Virtual management of the WAN with “zero touch” provisioning at the remote office
  • Integration of third-party VPN, firewalls, web gateways, WAN controllers, and other services

A key driver of adoption is the projected cost reductions of SD-WAN compared with a traditional network architecture. Some early adopters are seeing savings in excess of 50%. The efficiencies are achieved because:

  • SD-WAN enables the use of less expensive, commodity routers and replaces dedicated hardware, such as WAN path controllers, at remote sites.
  • It reduces organizations’ reliance on more expensive, private connections, such as MPLS.
  • Deployment is easier and more cost-efficient.
  • Central management capabilities make network changes simple to implement.
  • Virtual management reduces staffing needs at remote sites.

Adoption Accelerants and Decelerants

SD-WAN is definitely powerful, but also new and not yet widely adopted. But the technology is on its way up. Gartner predicts 50% of routers will be replaced with SD-WAN by 2020.

Helping advance the technology is the array of off-the-shelf products coming to market. There are several prominent OEMs in the space, including Cisco, HPE, and Juniper Networks, as well as startups and specialists. This is making SD-WAN surprisingly—although not completely—turnkey.

The timing of SD-WAN adoption, however, may be slowed due to two common factors in networking. First, long-lived ASICs devices used to control WANs and LANs may delay SD-WAN for organizations with a large investment sunk in such equipment. The other barrier will be carrier contracts. Many enterprises large enough to enjoy savings by favoring cheaper broadband connections over expensive private ones are currently locked in for multi-year agreements. They’ll have to wait for those contracts to expire before negotiating new deals incorporating the savings that will make SD-WAN realistic.

That being said, once hardware ages and telecom contracts are up, SD-WAN will be ready for prime time and attractive to a wide variety of multi-site enterprises.