Any recent event or article discussing trends in networking technology is sure to mention SD-WAN.
If you’re not familiar, SD-WAN is a software-defined approach to networking and is currently one of the hottest enterprise networking technology trends. It provides a networking solution that lays over traditional network infrastructure to optimize and simplify the management of a wide area network.
Today it is most commonly used to connect two branch locations of an organization but can also be used to connect cloud infrastructure to other cloud or on-premise data centers.
Companies of all sizes are looking at SD-WAN as the next evolution of their networking technology. This is evidenced by the fact that the market is growing by over 30% year over year.
The challenge that many companies face when selecting SD-WAN vendors is that not all SD-WANs are created equal. The term has not standardized on what qualifies as SD-WAN and what doesn’t. Further complicating things is the fact that there is not a sole SD-WAN vendor packaging all of the most common features into a single solution to rule them all.
So what does this mean for those tasked with looking into SD-WAN vendors?
It means that this is not yet a commoditized offering and that organizations must approach their research with a thorough understanding of their objectives and use cases before looking at vendor offerings.
As the industry begins to sort itself out, solutions are falling into a few different buckets. The following list can help identify the different offerings on the market.
1. Branch-to-Branch SD-WAN
Companies who need a continuous, high-throughput connection from one office to another office have historically relied on VPN tunnels or MPLS circuits.
Replacing these solutions with branch-to-branch SD-WAN can reduce the cost and burden of managing branch office connectivity. Branch-to-branch solutions are the most common SD-WANs on the market today and are often what many think of when SD-WAN is mentioned. In this configuration, SD-WAN enabled end points use software to provide virtualized network functions over existing internet connections.
If a company must connect multiple on-premise data centers or cloud environments that they control, this is the ideal SD-WAN to choose. This solution can run over any available internet connection including MPLS, standard broadband or even 4G and LTE. The SD-WAN is laid over this infrastructure and routes traffic over all available connections and is even able to prioritize traffic (QoS) to leverage the best connection available at any given time.
- Load balancing across multiple data connections
- QoS prioritization of application traffic across the WAN
- Secure, high-throughput connections between two branch offices or cloud environments
- Ability to send traffic over all available internet connections to optimize flow
2. Dedicated Network SD-WAN
In a dedicated network SD-WAN, a solution provider is offering access to a dedicated high- throughput backbone with some of the features of an SD-WAN like QoS, centralized visibility and policy management of all connections. This means that the network is structured similar to an MPLS circuit with additional management and security capabilities.
Typically provided by an internet service provider (ISP), these networks can reduce latency for applications that depend on low-latency connections. They leverage the benefits of a dedicated circuit, but similar to the branch-to-branch SD-WAN, can lay over multiple network pipes to optimize traffic based on priority and availability of a connection.
Companies that have bandwidth intensive applications that require high availability and low latency will be best served by a dedicated network SD-WAN. This type of connection requires that the organization have high degrees of control over both sides of the connection, but does leave deployment in the hands of an ISP, which can be slow to deploy. Because a dedicated circuit is being used in addition to the related SD-WAN software, the cost of these SD-WANs can be high.
- Tightly integrated with an ISP
- Multi-circuit/ISP load-balancing
- Real-time, low latency traffic
- Allows all environments to be seamlessly and redundantly connected
3. Application-Centric SD-WAN
Applications being served from the cloud often require access to a customer’s on-premise data. Because this data is not owned or controlled by the application provider, the WAN requirements come with a number of complexities. These customer environments can vary drastically in the policies, infrastructure and supporting IT staff available to maintain the connection.
Additionally, this connection needs to be secure, centrally controlled and supported, but cannot rely on the application provider having access to the customer’s environment to configure an initial connection.
In these cases, an application-centric SD-WAN can provide connectivity dedicated to a specific application. This form of SD-WAN does not serve all of an organization’s network traffic, but instead is dedicated to the service of a specific application. Because they serve applications, they are often designed with API frameworks allowing an application’s DevOps teams to programmatically control network features via APIs.
An application-centric SD-WAN is best applied to networks between two different organizations where centralized deployments, multiple stakeholders and heterogeneous environments must be supported. This solution can be used over any standard internet connection in place of dedicated circuits or IPSec VPN connections.
- Secure private connections to many different organizations
- Simplified deployment without the need for onsite IT resources
- Centralized and automated maintenance and support capabilities
- Network uptime is guaranteed with disaster recovery and multi-region failovers
- Ability to control network functions via APIs
As the SD-WAN space continues to define itself and coalesce around common sets of features, these areas seem to be the categories most likely to dominate going forward. Filtering by these simple buckets might be the quickest way to start comparing apples to apples. One model might not work for one area of an organization but be ideal for another.
When narrowing your selection, it is best to understand which features matter the most to you and then get some time with the product through a proof of concept. Most offerings allow for some form of a trial period. Understanding the way your existing network will be affected by your chosen solution is critical, and taking the word of the vendor's salesperson is not sufficient; talk with other clients and/or your trusted partners. Don’t just assume that the vendor who sold you your hardware-based infrastructure is best equipped to deliver a software-defined solution.
Moving to SD-WAN can save lots of time, money and actually improve the operations of an organization, but it doesn't come without challenges. Focusing on your use case can eliminate some of those challenges and streamline the modernization of your network.