Cellular drives SD-WAN technology for enterprise networking forward, with adaptive networking still to come
Just as vehicles have evolved to accommodate increased standards of safety and navigate through a variety of terrain, SD-WAN technology has been taking hairpin turns along the winding path of rapidly expanding networks. Although the SD-WAN evolution never veers too far from its foundational characteristics of WAN optimization, link bonding, traffic handling, and tunneling, today’s SD-WAN story is enriched by the capabilities of 5G.
The origin story of SD-WAN for enterprises
SD-WAN evolution did not occur overnight. This technology — originally invented to help enterprises transition from high-cost multi-protocol label switching (MPLS) links to more affordable broadband links — has been around for more than a decade. Thanks to its ability to bring reliability to broadband circuits by leveraging multiple connections, providing network failover, and increasing link diversity, SD-WAN architecture was quickly adopted by enterprises in nearly every industry.
SD-WAN technology provided a highly anticipated means of leveraging any combination of WAN transport links to securely connect users to applications. It also supplied a way to consider application characteristics and the conditions of various WAN connections in order match each application with the most appropriate connection based on security, bandwidth, and business needs — a feature known as traffic steering.
These characteristics helped facilitate the transition from on premises applications in the data center to cloud-based applications, allowing branch locations to connect directly to the cloud rather than backhauling traffic to the data center first.
Like the rest of the world in 2020, SD-WAN technology had to pivot in order to support the transition of workers from headquarter and branch locations to home offices. Technology must now also meet the demands of enterprises who are known to use up to 1,000 SaaS or cloud-based applications at a time — and those demands show no sign of slowing.
SD-WAN technology in today’s world
Once primarily considered to be a failover connection, cellular is now being used for primary and secondary WAN connectivity due to the flexibility and time to service advantages that it provides.
Because the main objectives of today’s SD-WAN solutions are to enhance application quality of experience (QoE) while still improving connection resiliency, the success of SD-WAN technology teeters on its ability to support the scale and mobility that is accelerated by the continued build-out of 5G networks. With this in mind, SD-WAN evolution must:
- Consider cellular-centric attributes — such as available bandwidth and data usage when steering traffic — to enable more cost-effective and reliable 5G networking.
- Preserve bandwidth by using in-line traffic to calculate WAN performance metrics while preventing impacts on data plans and eliminating the burden of manual data measurements.
- Incorporate comprehensive cellular insights including visibility into service providers, signal strength, and router and serving cell tower locations to ensure optimal device placement.
What is network slicing and how does it fit into the story of SD-WAN evolution?
To roll out 5G quickly, many carriers built 5G towers with an LTE core. However, by the end of 2023, many service providers will start rolling out 5G cores, creating a true 5G experience that includes the ability to support 5G network slicing. Support for standalone network cores and network slicing is a key component of how SD-WAN needs to evolve to support 5G growth.
Network slicing refers to the ability to carve out pieces of the network based on use case and traffic patterns. Slices may be categorized by various combinations of bandwidth, signal strength, jitter, latency, and more. For example, one slice may be optimized to support endpoints processing massive amounts of IoT data, while another is built to accommodate mission-critical communications, while yet another is designed to handle traffic with low-latency needs such as video surveillance.
SD-WAN provides the intelligence to recognize, classify, and create a policy to steer the applications and traffic to their appropriate network slice. For example, an enterprise may designate Microsoft Teams to a slice with more bandwidth and lower latency if that is the company’s primary mode of communication. The policies assigned via an SD-WAN management system will then recognize when an authorized user is attempting to connect to Teams, and steer that traffic to its designated slice.
Network slicing is not yet widely available across the globe. Amid its expansion, LTE Packet Data Networks, or PDNs, offer an alternative way for enterprises to dip their toes into providing differentiated services for their applications by subscribing to multiple PDNs on a single modem and being able to recognize and steer applications using cellular-optimized SD-WAN technology.