In the midst of growing numbers of offices, cloud platforms, distant locations, and scattered workforce, WANs have become increasingly critical and complex. Classic WAN infrastructure has served as the backbone of enterprise connectivity for several decades now, but evolving application requirements are forcing organizations to rethink their network design strategy. In case you require greater flexibility within your network design, you may consider leveraging SD-WAN Solutions for business environments.
SD-WAN (Software-defined wide area networking) is a concept where the software plays an essential role to manage the network, control the traffic flow, and utilize various connectivity choices. The conventional WAN (wide area network) on the other hand, is based more on hardware routing and path through networks.
What Is a Traditional WAN?
A traditional WAN is the kind of WAN where geographically separated locations such as branch offices, corporate headquarters, and data centers are connected using dedicated networks. In the past, the most common technology used by organizations for such connectivity was Multiprotocol Label Switching (MPLS).
With a traditional WAN, the flow of data in the network would always follow certain routing policies. Changes in the configuration of the network equipment were carried out in the network administrator’s office at the physical level.
What Are SD-WAN Solutions?
In SD-WAN solutions, a software-defined control plane operates on top of underlying network hardware. Rather than viewing each WAN link in isolation, it can analyze the available links and implement policies based on application needs and network conditions.
The SD-WAN framework can operate with private circuits, broadband, and wireless links. Thus, businesses have greater freedom in configuring and extending their WAN networks. One more feature that differentiates SD-WAN from regular WANs is centralized management. Network administrators can create policies centrally and implement them throughout the network.
SD-WAN vs. Traditional WAN: Key Differences
The main differences involve traffic management, connectivity, scalability, visibility, and administration.
| Feature | Traditional WAN | SD-WAN |
| Network management | Often device- and site-based | Centralized, software-driven management |
| Traffic routing | Primarily follows established routes | Can dynamically select paths based on policies |
| Connectivity | Often centered on dedicated circuits | Can combine multiple connection types |
| Application awareness | More limited | Can apply policies to application needs |
| Scalability | Expansion may require manual configuration | Centralized policies simplify expansion |
| Cloud connectivity | May route through centralized infrastructure | Supports flexible cloud and internet access |
| Visibility | Often distributed across devices | Centralized monitoring can improve visibility |
| Network changes | Frequently require device-level work | Policies can be managed centrally |
Traffic Management: Fixed Paths vs. Intelligent Routing
One of the major differences between two approaches is in their handling of traffic flows. Classic WAN systems tend to work using fixed routes. Although there are routing protocols that can adapt to network changes, the administrator may have limited abilities to govern the way each particular application uses the available bandwidth.
SD-WAN can make use of an application-aware method of managing traffic flows. Network policies can be made to give priority to critical applications and make selections of the route based on the criteria like latency, packet loss or availability. In case of changing circumstances, traffic could switch to another route.
This function becomes handy when the organization uses multiple types of connectivity. Rather than relying solely on one type of connection, it can combine all possible connections and create the policies for their usage.
Connectivity and Cloud Access
Conventional WAN architectures typically developed from private connectivity among known locations. This is still a valid architecture for situations where private connectivity is paramount. However, many modern enterprises now function beyond the constraints of the traditional corporate data center. Applications are hosted either in private or public clouds, whereas users may be located in branches, at home, or elsewhere.
SD-WAN enables a software layer that operates across different transport layers. This allows organizations to develop an architectural design independent of the specific transport layer and can make it easier to connect distributed locations to cloud services. Rather than basing the design of the WAN on a central location, it makes more sense to develop a policy based on where the users and applications actually reside.
Management and Scalability
Manual management of a limited number of WAN sites may be feasible. When a company grows, however, this may result in increased burden for administrators. In classic network architectures, administrators are responsible for setting up each individual device, configuring routing policies, resolving connectivity issues, and managing all of these activities across different sites.
SD-WAN moves much of this burden to central coordination and management. Administrators set up policies centrally and distribute them across the entire network.
Visibility and Troubleshooting
Network visibility is important as well. With the typical WAN infrastructure, the process of troubleshooting can require inspecting separate routers, connections, and network segments.
SD-WAN architecture can offer centralized visibility for network paths and application performance. Monitoring can assist in identifying problems related to latencies, packet loss, availability, or changing links.
In case of further reading, an independent SD-WAN overview offers useful technical information.
Security Considerations
The upgrade of networks should not be done for performance alone. The additional connectivity can present additional security considerations.
The architecture of WAN has typically put the security controls at the central network. With increased traffic going from branch offices, cloud apps, and the internet, there is a consideration of how security policies apply to various paths.
Since SD-WAN is an architectural solution, the level of security may differ depending on the type of implementation. Businesses need to consider what role will be played by traffic inspection, segmentation, access control, encryption, and enforcement of security policies in the overall architecture. An SD-WAN architecture guide will give more insight into software-defined networking solutions.
When Should an Organization Consider SD-WAN?
The adoption of SD-WAN can become appropriate in cases where the organization faces issues that cannot be efficiently solved by using the traditional WAN design. These issues are typically:
- An increasing amount of branch or remote sites
- Growing reliance on cloud and SaaS applications
- Several WAN connections that need to be managed centrally
- Problems with implementing consistent policies for the network
- Insufficient monitoring of application and link performance
- The need for increased network agility
Although, SD-WAN may not necessarily be the best solution for all businesses. Network assessment must take into account the current infrastructure, application needs, security framework, connectivity, experience level, and future growth potential.
The Transition Does Not Have to Be All or Nothing
A step-by-step approach doesn’t require organizations to upgrade their whole WAN all at once; rather, it allows for SD-WAN implementation together with the old architecture and gradual transition to applications or locations.
This can allow teams to gauge policies, assess performance, and determine operational needs before scaling up.
Choosing the Right WAN Architecture
The choice between traditional WAN and SD-WAN shouldn’t be made based on technology preferences but on business and technical needs. It’s necessary to evaluate the number of sites that your company operates, location of the applications, users’ access to these applications, and policy changes frequency.
While the traditional WAN is still relevant for organizations requiring predictable network paths and private connectivity,
The SD-WAN architecture seems to be better for flexible and centralized management and management of application-aware traffic and cloud services.
In any case, your choice will depend on the network and business future of your company. In a distributed environment, software-based network management can play an important role.
FAQs
1. Is SD-WAN replacing traditional WAN?
An SD-WAN does not always mean that it will replace traditional WAN. Rather, it is an overlay management and traffic control software layer that works on multiple types of physical connections.
2. Is SD-WAN faster than traditional WAN?
SD-WAN does not necessarily increase the speed of an existing network path in itself. It is because of the way SD-WAN is capable of monitoring the paths that are available to it and applying policies to its traffic.
3. Does SD-WAN require an internet connection?
Not really. SD-WAN solutions support various network transport services such as private, broadband, and wireless networking. The companies will be free to choose the best-suited network type for their needs.
4. What should organizations evaluate before adopting SD-WAN?
Organizations must assess their application needs, existing WAN infrastructure, connectivity choices, security architecture, network visibility, scalability, operations, and costs. The insight into the current challenges organizations face is needed to understand if there is a need for SD-WAN at all.
