The Network Edge: Stretching the Boundaries of SD-WAN

The advent of SD-WAN has dramatically disrupted the enterprise networking landscape in the last five years. Industry experts and analysts opine that it is unlike anything they have seen in decades in the networking arena. Leading SD-WAN solutions have enabled dramatic real-time application performance improvements, simplicity, and automation for implementation and management of wide-area networks, and optimized cloud access.

However, SD-WAN technology is still evolving. New functionalities and integrations are being added at a rapid pace. The boundaries of SD-WAN are now stretching deeper and broader beyond just the WAN edge into the "Network Edge." The Network Edge is enabling the next wave of network transformation by absorbing new functions including compute, analytics, security, and multi-cloud, that are all critical to supporting enterprise locations where business is conducted.

In SD-WAN implementations organizations deploy an edge device at the branch, and edge devices close to their workloads – the public cloud, and the data center – to create a mesh of connections between locations with direct access to the cloud that avoids backhaul to the corporate data center. Optionally, they can place a virtual edge device in the cloud, to provide additional control and optimization for IaaS hosted applications. SD-WAN is managed from a central console using templates and automation. This approach to network design and simplified management is vital to the evolution of the WAN from a traditional hub and spoke that was difficult to configure, especially at scale, and limited in how it served applications in the cloud.

Given where SD-WAN resides strategically in the network and its management capabilities, SD-WAN has become the platform of choice for the evolution of the network edge. Let’s look at how the edge is developing and how advanced SD-WAN solutions make this evolution possible.

The need for edge compute services

The “branch” has evolved beyond the traditionally understood branch office confined by four walls. The Internet of Things (IoT) and mobility are redefining the branch which can now be an agricultural field with machines and devices that interact with each other. This new paradigm has increased requirements for edge services. This has created the option for the edge to go deeper into the branch office and cross over the LAN boundary to support IoT device traffic. This approach needs an advanced SD-WAN platform that is capable of delivering compute services at the edge. With edge compute, one major challenge is how to manage deployment and configuration of services. Advanced SD-WAN solutions such as VMware SD-WAN provide a virtualization infrastructure for hosting the services and centralized management of the platforms so that edge compute services can easily be delivered. 

The need for quick access to broadband

While transport independence is a hallmark of SD-WAN, easy access to broadband is a growing requirement of the edge. There is an emerging approach that could leverage 5G for a low latency connection and on-demand control. It will be possible to deploy 5G in a very short time compared to landlines, making it ideal for use cases such as pop-up stores and temporary field sites. 5G will be versatile, too. Organizations will be able to specify on the fly what type of throughput and network characteristics they want. Once that is done, the right link configuration is automatically applied to deliver the specified connection. 5G would allow advanced SD-WAN platforms to consider the network underlay as not just one underlay, but a configurable underlay. It is programmable so organizations can ask for the specifications they need with regard to bandwidth and traffic handling. The ability to run an overlay with the intelligence of SD-WAN counting on the underlay intelligence of 5G is revolutionary. This approach is focused using 5G as a transport mechanism for enterprise data, not 5G consumer phones.

The need for multi-region networks

Continuing with the evolution of how applications are accessed, one can see a need to span telco networks to serve the needs of global corporations. This will be achieved by using a federation of VMware SD-WAN Gateways to create an over the top (OTT) service that can interoperate gateway to gateway connecting independent telco networks. For example, if one telco network doesn’t reach a geography where the corporation has a presence, then the organization can use the federated gateways to link to other telco networks. These federated gateways extend the telco’s network beyond the facilities that they own, creating a global virtual WAN in a telco-to-telco federation.

The need for a service delivery platform

The next piece of the SD-WAN evolution is SD-WAN as a platform. There are many services that organizations need to run at their branch offices. However, they have a concern about device sprawl and ease of management of these services. Deploying a service as a virtual network function (VNF) eliminates the need for separate hardware at the branch office location. Again advanced SD-WAN solutions such as VMware SD-WAN provide an NFV infrastructure for this, making deployment and management easy. This allows organizations to deliver additional services from the edge platform. Network analytics is a popular choice for this type of service. Companies can take analytics from the edge SD-WAN platform and correlate them with analytics from other devices such as servers, end-user devices, switches, and routers, to check for anomalous behavior and discover the root cause. This can be used to reduce the time to resolve network performance issues greatly. With SD-WAN as a platform, organizations can deploy virtualized functions and manage them from the same console.

The need for a hybrid and multi-cloud

The final evolution in access to applications that SD-WAN needs to support is hybrid and multi-cloud integration. As organizations continue to increase their use of the cloud to host applications and use SaaS applications, direct access with high performance is critical. Applications that are hosted in the public cloud or if the organization is using SaaS applications can use advanced cloud-hosted multi-tenanted SD-WAN gateways to direct traffic to these applications. The gateway does the traffic steering and provides optimizations between it and the edge device.

There are some instances where part of the application resides in the data center and part resides in the cloud, creating a hybrid cloud model. In this case, SD-WAN needs to create optimized connections to both locations and handle traffic steering appropriately. Furthermore, some organizations utilize multiple clouds for hosting the applications, so the SD-WAN solution needs to provide optimized connections to each of the clouds and manage traffic to and between them.

The vision for the edge

These evolutionary areas are where we see SD-WAN headed, and we call this direction the new Network Edge because it's beyond the traditional SD-WAN functions. It includes edge computing, fast deployment of intelligent high-speed connections, SD-WAN as a broader service delivery platform, connecting multiple networks, and integrating with hybrid and multi-cloud models. These are all aspects of features that go beyond the definition of today’s SD-WAN and enable the evolution of the WAN.