Our Thinking | Intercity Technology

Why legacy networks are the hidden handbrake on UK business, and where SD-WAN fits

Written by Intercity | Feb 16, 2026 7:53:27 PM

Our connectivity experts weigh in on why most IT leaders in the UK are feeling the strain of networks that no longer match the pace of their organisation.

Applications run in the cloud. Users work from anywhere. Operations depend on real‑time data. Yet many businesses still rely on legacy WAN designs built for a slower, more predictable era.

The reality is straightforward. Legacy networks slow UK businesses down because they cannot deliver the speed, resilience, flexibility, or security that modern operations demand. They create drag every day through latency, downtime, and complexity. Modernising the network removes those barriers and lets the business run at the speed it needs to.

 

 

 

Legacy networks were built for a world that no longer exists

Traditional WANs (Wide Area Networks) were designed when most applications lived in a central data centre. Traffic flowed from branch to core, and performance expectations were far lower. Today, traffic flows directly to cloud platforms and Software as a Service (SaaS), and users expect applications to work instantly.

Legacy MPLS (Multiprotocol Label Switching) circuits create bottlenecks because they force traffic back through central points, adding delay and cost. By contrast, SD-WAN (Software Defined Wide Area Networking) uses intelligent routing to steer traffic across multiple connections, including broadband and 5G, based on application needs. This improves speed, reduces cost, and keeps performance predictable.

 

 

Hidden downtime creates real operational loss

Most downtime is not dramatic. It is a series of small interruptions that drain productivity, revenue, and customer experience.

In manufacturing, slow or unstable connectivity interrupts OT (Operational Technology) systems such as SCADA (Supervisory Control and Data Acquisition), PLCs (Programmable Logic Controllers), robotics, and industrial IoT. Every second of latency reduces key metrics like OEE (Overall Equipment Effectiveness) and FPY (First Pass Yield).

In retail, poor connectivity hits POS (Point of Sale) systems and store Wi‑Fi, creating queues and lost sales.

In logistics, disruptions affect WMS (Warehouse Management Systems), TMS (Transport Management Systems), telematics, and vehicle routing. That delays deliveries and reduces On Time Delivery (OTD) performance.

Modern SD-WAN architectures fix this through redundant links, automatic failover, and prioritisation of critical applications. The result is a smoother, more predictable operation that absorbs outages instead of exposing them.

 

 

Business expansion should not be slowed by network lead times

Few organisations grow in a straight line. They open new stores, depots, offices, clinics, and temporary sites. They relocate teams. They merge, acquire, and consolidate. Legacy networking makes every change slow and expensive because each new connection requires manual engineering, long waits, and inconsistent configuration.

SD Branch simplifies this. It combines LAN, Wi‑Fi, security, and routing under central management. Teams can deploy new sites using zero‑touch provisioning, and policies are applied consistently from day one. It shortens the time from idea to operation.

 

Security has outgrown the old perimeter model

Threats evolve faster than legacy networks can cope with. Traditional designs rely on central firewalls and fragmented controls that are difficult to maintain across multiple sites, cloud services, and remote users.

This is where SASE (Secure Access Service Edge) becomes essential. It brings network security into the cloud so policies are enforced consistently everywhere. Sensitive environments, such as OT networks in manufacturing, can be segmented and isolated to reduce the risk of cyber‑physical incidents.

This removes complexity for IT teams and strengthens the organisation’s overall posture.

 

Why this matters now for UK organisations

The pressure on networks has never been higher. Cloud adoption continues to rise. Remote working has become normal. Customer expectations have tightened. Boards demand robust cyber security. Regulators expect strong controls for environments handling payment data (PCI DSS) and personal information (GDPR).

Modern networks deliver resilience, efficiency, and consistent security policies that help organisations meet these expectations. Legacy designs cannot adapt at the speed required.

 

The network directly affects the KPIs leaders are judged on

Every leadership role depends on the network in a different way.

  • Manufacturing leaders rely on connectivity to maintain OEE, FPY, throughput, and safety.
  • IT leaders need visibility, predictable costs, strong security, and low MTTR (Mean Time To Resolution).
  • Retail operations teams depend on store uptime, fast checkouts, and seamless customer experiences.
  • Supply chain and logistics leaders focus on OTD, OTIF (On Time In Full), inventory accuracy, and faster recovery during disruptions (RTO and RPO).
  • Professional services leaders need flawless collaboration, fast cloud applications, and more billable hours.

A modern network strengthens the KPIs that matter most to each part of the organisation.

 

The modern network stack explained simply

A modern design combines three core components:

  • SD-WAN: Routes traffic intelligently across any connection, chooses the best path for each application, and provides automatic failover for continuity.

  • SD Branch: Unifies Wi‑Fi, LAN, and security into one managed environment, simplifying site operations.

  • SASE: Applies cloud delivered security consistently to every user and site, with real time policy enforcement and segmentation for critical systems.

Together, these create a network that is faster to deploy, easier to manage, and more resilient in daily operations.

 

What good looks like in practice

  • High availability through diverse links and automated failover
  • Direct access to cloud and SaaS without unnecessary backhaul
  • Lower operational overhead through centralised control
  • Better visibility of traffic and issues across all sites
  • Consistent security controls with simpler compliance
  • Faster deployment for new sites using zero‑touch methods

 

A controlled, low risk path to modernisation

Modernising the network does not need to be disruptive. A staged approach works best. 

Step 1: Assessment
Identify what is holding the network back and where improvement will have the biggest operational impact.
Step 2: Outcome based design
Link the design to KPIs that matter to the business, not just to IT metrics.
Step 3: Phased deployment
Use zero‑touch provisioning and failover strategies to move sites safely without interrupting operations.
Step 4: In life management
Operate the network through clear SLAs (Service Level Agreements), performance reporting, capacity planning, and ITIL4 (IT Infrastructure Library v4) aligned change control.

 

WHAT NEXT?

The simplest, least risky way forward is a network assessment. It provides a clear view of where legacy design is creating drag, where modernisation will unlock the biggest value, and how to make the transition without operational disruption.

It gives you clarity, reduces uncertainty, and helps you move the business forward with confidence. The handbrake comes off. The organisation runs faster.