What is SD-WAN?

Software-defined WAN (SD-WAN) applies software-defined networking (SDN) concepts to wide area network (WAN) connections. SD-WAN technology abstracts traffic management and monitoring from network hardware and applies them to individual applications to achieve improved app performance, deliver high-quality user experiences over geographically dispersed locations, and simplify the deployment of wide-area and cloud-access networks.

How does SD-WAN work?

Modern enterprises rely on wide area networks to support an increasing number of business-critical applications, such as virtual desktops, VoIP and video conferencing platforms, ERP and CRM systems, and other enterprise or cloud-based apps. These applications often are bandwidth-intensive and demand high reliability and quality of service. When they slow down for even a few seconds, employees notice, and productivity suffers.

The traditional way to address WAN constraints and meet performance and reliability requirements is to upgrade network bandwidth. But this isn’t cost-efficient and doesn’t prioritize mission-critical applications. It also doesn’t address the changing nature of applications and data, which are increasingly located in public and private clouds.

SD-WAN technology allows you to create a hybrid WAN architecture that binds multiple MPLS, mobile, and broadband paths together to provide a single, logical, virtualized path that can dynamically adapt to network conditions. It also enables priprioritization decisions for each application using very granular application classification to ensure that the highest-priority applications always perform extremely well. As the next-generation alternative to WAN optimization, SD-WAN technology addresses evolving application and branch infrastructure requirements.

SD-WAN benefits

SD-WAN solutions offer many benefits to meet the demands of modern enterprise networks, including:

  • Improved application performance and quality of service for remote and branch workers
  • Reduced WAN costs and scaled capacity through the use of lower-priced broadband and mobile connections
  • Increased flexibility to prioritize business-critical applications over other network traffic
  • Improved business continuity and disaster recovery capabilities that maintain connectivity even during multiple network failures
  • Increased connection security across the WAN as applications and data migrate to the cloud
  • Reduced branch networking complexity by consolidating services into an integrated WAN edge appliance and centralizing management and policy definition

SD-WAN vendors

Changing business needs are driving network evolution. Traditional WANs were not designed for today’s demands for increased flexibility, responsiveness, security, and control. SD-WAN technology is an effective and economical solution that addresses these challenges. The SD-WAN vendor market is growing quickly and includes offerings from large networking vendors, focused WAN specialists and venture-funded startups. It is estimated that the SD-WAN market will be worth more than $6 billion in 2020.

Learn about Citrix NetScaler SD-WAN

Increase WAN throughput and reliability while improving the application experience for branch and mobile users with NetScaler SD-WAN.

Related terms: Software-Defined Networking (SDN), branch office networking, business continuity, WAN edge

Additional SD-WAN education resources:

Back to Glossary