What Is SD-WAN and When Should a Business Use It?

SD-WAN, or software-defined wide area networking, is a way for businesses to centrally manage how network traffic travels between multiple sites, cloud services, data centres and internet connections. A business should consider using SD-WAN when it operates across several locations, relies on cloud or business-critical applications, uses more than one connectivity provider or needs greater control over network resilience and failover.

The platform applies central routing policies across the available connections. This allows different applications to use a suitable path based on factors such as latency, packet loss, jitter and availability. The main SD-WAN benefits include simpler multi-site management and application-aware routing. A common policy framework can also accommodate different access technologies. Where suitable backup routes are available, it can improve resilience and support more direct cloud connectivity.

At APC Communications Solutions, we design and manage SD-WAN and hybrid connectivity for complex or business-critical networks. We assess existing circuits and application requirements across your sites, including resilience needs. Where appropriate, we can combine fibre, microwave internet, fixed wireless access, 4G, 5G and satellite in a design built around your operational requirements.

What Is SD-WAN?

A wide area network, or WAN, connects users and systems across separate locations. SD-WAN applies software-defined control to that network, allowing much of the routing policy to be managed centrally rather than configured separately at every site.

Those policies can control which routes applications use and how traffic should respond when performance changes. They can also determine when an alternative connection should take over. This gives organisations a consistent way to manage a distributed network even when individual sites use different carriers or access technologies.

How Does SD-WAN Work?

• The underlay: The underlay is the transport network beneath the overlay. Depending on the site, that could include fibre, business broadband, microwave internet, fixed wireless access, 4G, 5G, satellite or MPLS.
• The overlay and central policies: The overlay is the logical network created across those connections. An edge device or virtual appliance at each location applies centrally defined policies, so routing rules do not have to be managed independently at every site.
• Application-aware routing and failover: The platform can measure conditions such as latency, packet loss and jitter and use that information when selecting a route for an application. If a route fails or falls outside configured performance thresholds, traffic can move to a suitable alternative path.

Latency measures delay, while jitter describes variation in that delay. Packet loss occurs when data fails to reach its destination. A voice or video application may therefore use a lower-latency path while less time-sensitive traffic uses another. Any failover path still needs enough capacity for the applications moved onto it.

What Are the Main SD-WAN Benefits?

This approach allows connectivity across multiple sites to be managed as one coordinated WAN, with routing shaped around application requirements.

When Should a Business Use SD-WAN?

Complex multi-site estates: As an estate grows, separate circuits and routing rules become harder to manage consistently. A central policy framework can manage those locations while allowing each site to use the connectivity that suits it.

• Business-critical applications: Cloud telephony, video, hosted applications and other business-critical services do not all tolerate delay or packet loss in the same way. The network can prioritise suitable paths and use an alternative route when the design includes one.
• Different sites need different connection types: Not every location has the same fibre availability or deployment constraints. A software-defined architecture can bring different access technologies into one managed WAN rather than forcing every site onto an identical circuit type.
• Cloud use or site growth is making the existing WAN harder to manage: A network that backhauls branch traffic through one central location can become inefficient as cloud use grows or sites are added. The architecture can support more direct internet access and make it easier to incorporate interim or alternative connectivity.

When Might It Be Unnecessary?

A single-site business with one suitable connection and simple routing needs may gain little from a full platform. If the aim is only to restore essential access after a primary circuit fails, a managed backup or simpler hybrid internet design may be more proportionate.

SD-WAN vs MPLS: What’s the Difference?

SD-WAN and MPLS are not direct equivalents. MPLS, or multiprotocol label switching, is a packet-forwarding technology commonly used by service providers to deliver private WAN connectivity. The software-defined architecture can operate across MPLS or other transports.

Some organisations reduce their reliance on MPLS by introducing public internet services or wireless connectivity. Others retain MPLS for particular sites or applications because it still meets their performance needs or fits existing contracts and network requirements.

The right choice depends on the applications, existing infrastructure, route diversity, support model and commercial objectives. The software-defined architecture can complement MPLS, replace parts of an MPLS estate or operate without it.

Cloud Applications and Internet Breakout

Cloud-first organisations often send more traffic directly to services such as Microsoft 365 and other software-as-a-service platforms. Routing every branch through a central data centre can add distance and consume central bandwidth.

The architecture can allow approved traffic to break out to the internet locally, while private traffic continues across the corporate WAN. Security controls still need to be built into the design, including any required inspection or filtering.

Why the Underlay Still Matters

The platform can choose between available routes, but it cannot increase an individual underlay connection’s capacity. It also cannot create genuine route diversity where the underlying services do not provide it.

This is where connectivity engineering matters. APC can combine fibre, microwave internet, fixed wireless access, 4G, 5G and satellite where site conditions and operational requirements justify that approach. The design should consider capacity, application sensitivity, deployment timescale and likely shared failure points before deciding which connections the platform will manage.

How MultiConnect+ Manages Multiple Connections

APC delivers managed hybrid connectivity through MultiConnect+. It uses SD-WAN to manage multiple connections and combine access technologies where appropriate.

Where a full deployment is unnecessary, APC can provide hybrid internet or business internet backup, with individual connectivity services available where that is more appropriate. The aim is to match the architecture to the operational requirement without unnecessary complexity.

Explore the Right WAN Design for Your Organisation

At APC can assess your network requirements and existing circuits before recommending an appropriate design. That may involve MultiConnect+, managed WAN, hybrid internet or a simpler backup strategy.

Contact APC to discuss your connectivity requirements.

Frequently Asked Questions

What does SD-WAN stand for?

It stands for software-defined wide area networking. It uses software-defined policies to control how traffic moves across a WAN.

Does it replace MPLS?

Not necessarily. MPLS can remain one of the underlying transports in the design, while other organisations may reduce or remove it.

Does it need two internet connections?

No. The architecture can operate over a single transport. Its resilience and path-selection benefits become more useful when a site has more than one suitable connection.

Is it secure?

These platforms can use encrypted tunnels and network segmentation. They can also integrate with wider security services, but those capabilities do not replace a complete network security strategy.