How to Build a More Resilient Network Without Disrupting the Business

Why modern network architecture matters when uptime, security and remote access are business-critical

For organisations operating across multiple offices, datacentres and cloud environments, network resilience is no longer simply an IT consideration.

When employees rely on secure access to applications and systems from offices, homes and locations around the world, even a short outage can have a significant operational impact. At the same time, security teams need to be able to respond quickly to vulnerabilities and apply critical updates without waiting for lengthy maintenance windows.

So, how do you modernise a complex network infrastructure without introducing unnecessary risk or disrupting the business?

A recent infrastructure transformation for international law firm Trowers & Hamlins provides a useful example.

The challenge: modernising without creating more complexity

Trowers & Hamlins has more than 170 partners and over 1,000 employees across the UK, Middle East and Asia.

As the firm reduced its primary office and datacentre footprint and moved core datacentre services into a dedicated co-location facility, it had an opportunity to rethink its underlying network architecture.

The existing environment consisted of two separate datacentre networks, with a limited number of networks stretched between them.

While this architecture had supported the organisation’s requirements, the changing IT landscape created an opportunity to simplify the environment and improve resilience.

The key objectives were to:

• Remove critical single points of failure
• Improve network resilience and availability
• Simplify the datacentre architecture
• Increase capacity for remote users and branch offices
• Improve support for cloud-connected services
• Reduce the impact of planned maintenance
• Make security updates easier to implement
• Create a more scalable platform for future growth

Rather than simply moving the existing infrastructure into a new location, the firm wanted to use the datacentre relocation as an opportunity to build something better.

Why single points of failure matter

A single point of failure is any component, connection or dependency that can cause a wider service disruption if it fails.

In a modern enterprise environment, these dependencies can exist at multiple levels — from network hardware and connectivity to security infrastructure, authentication services and datacentre architecture.

The challenge is that some single points of failure aren’t obvious until something goes wrong.

A network can appear highly available while still relying on a critical component that requires downtime during maintenance or upgrades.

For organisations where systems need to remain available around the clock, this creates a difficult balance between security and availability.

You need to patch vulnerabilities.

But you can’t afford unnecessary outages.

Security maintenance shouldn’t have to mean downtime

One of the key requirements of the Trowers & Hamlins project was to address the downtime associated with infrastructure maintenance.

Previously, routine security updates and maintenance could require approved maintenance windows. While planned downtime can be managed, it can also delay the deployment of critical security updates.

That’s particularly important when a vulnerability requires urgent remediation.

The redesigned architecture enables critical security updates to be carried out while services remain available.

This gives the IT team greater flexibility to respond to emerging vulnerabilities and reduces the operational impact of essential maintenance.

The wider lesson for security teams

Network architecture and cybersecurity are increasingly interconnected.

A security team may identify a vulnerability that needs immediate attention, but the ability to remediate it depends partly on the underlying infrastructure.

If applying a security update means taking a critical service offline, organisations may face difficult decisions about timing and risk.

A resilient architecture can help remove that compromise.

Designing resilience into the datacentre

ANSecurity worked with Trowers & Hamlins to design and implement a new logical datacentre architecture.

The objective was to move away from the previous model and create a single logical datacentre environment that could better support workload mobility and disaster recovery.

The transformation strengthened resilience across:

• Datacentre networking
• Branch office connectivity
• Remote user access
• Core security services
• Disaster recovery
• Cloud-connected workloads

The result was an environment designed not just around today’s requirements, but around how the firm’s infrastructure is expected to evolve.

Don’t combine every change into one migration

One of the most important aspects of the project was how the transformation was delivered.

Rather than attempting to redesign the architecture at exactly the same time as physically relocating the datacentre infrastructure, the programme was split into two phases.

Phase one: design, deployment and validation

ANSecurity first deployed and validated the new architecture.

This allowed the teams to test the environment, identify potential issues and refine the migration approach before the physical relocation took place.

Detailed migration plans and runbooks were developed collaboratively between ANSecurity, Trowers & Hamlins’ internal IT teams and specialist third-party providers.

Phase two: physical relocation

Once the new architecture had been validated, ANSecurity supported the physical relocation of infrastructure into the new co-location facility.

This phased approach reduced the amount of change taking place simultaneously and therefore reduced migration risk.

The move was completed with minimal disruption to business operations, with only minor issues encountered and resolved during the migration.

The impact on remote users

Modern network resilience isn’t just about what happens inside the datacentre.

For distributed organisations, remote access and branch connectivity are equally important.

More than 750 users access services remotely through Trowers & Hamlins’ application delivery platform.

The redesigned environment provides greater availability for remote access services while also increasing capacity and improving connectivity for branch offices.

This creates a stronger foundation for hybrid working, international operations and future growth.

Simplifying the infrastructure

Resilience doesn’t necessarily mean adding more technology.

In many environments, increasing resilience can actually involve reducing complexity.

The new architecture has helped Trowers & Hamlins simplify infrastructure management through:

• Centralised configuration
• Reduced duplication
• Standardised branch office deployments
• Increased network capacity
• A more consistent architectural model

This matters because complexity itself can introduce risk.

The more variations, dependencies and duplicated configurations an IT team has to manage, the harder it becomes to maintain consistency and respond quickly when something changes.

Seven years of partnership

The project also builds on a relationship between Trowers & Hamlins and ANSecurity spanning more than seven years.

ANSecurity has previously supported the firm’s global SD-WAN rollout, helping modernise connectivity across its international offices and reduce reliance on legacy WAN technologies.

That existing understanding of the firm’s infrastructure provided an important foundation for the latest transformation.

Rather than approaching the project as a standalone implementation, the teams could build on their understanding of the organisation’s existing architecture, requirements and future direction.

What can other organisations learn from this?

The Trowers & Hamlins transformation highlights several important considerations for organisations reviewing their own network architecture.

1. Don’t just migrate — modernise

A datacentre move presents an opportunity to question whether the existing architecture is still right for the organisation.

Simply replicating an old environment in a new location can mean carrying yesterday’s limitations into tomorrow’s infrastructure.

2. Look beyond hardware redundancy

True resilience isn’t just about having two pieces of hardware.

Consider the complete service chain — connectivity, security, authentication, applications, remote access, cloud services and operational processes.

3. Make security maintenance part of the resilience strategy

If critical security updates routinely require downtime, your architecture may be creating an unnecessary barrier to effective vulnerability management.

4. Reduce complexity where possible

Centralisation, standardisation and removing unnecessary duplication can make infrastructure easier to manage and potentially reduce operational risk.

5. Plan major migrations in stages

Separating architectural transformation from physical relocation can make it easier to validate changes, identify issues and reduce the risk of a major cutover.

Building infrastructure that’s ready for what comes next

Network infrastructure has changed significantly.

Organisations are supporting hybrid workers, cloud applications, international offices, increasingly complex security requirements and users who expect systems to be available wherever they are working.

That means the traditional approach of simply keeping the network running isn’t enough.

Organisations need infrastructure that can adapt, withstand disruption and allow security teams to act quickly when risks emerge.

The Trowers & Hamlins project demonstrates what can be achieved when network modernisation, resilience and security are considered together.

For organisations planning a datacentre move, network transformation or infrastructure refresh, the biggest question shouldn’t simply be “How do we move what we have?”

It should be:

“How do we use this opportunity to build a network that’s more resilient, secure and ready for the future?”

How ANSecurity can help

ANSecurity works with organisations to design, implement and support resilient network and security infrastructure.

Our approach combines strategic consultancy with practical implementation and ongoing support, helping organisations modernise their environments without losing sight of operational requirements.

From network architecture and datacentre transformation to firewalls, SD-WAN, vulnerability management and managed security services, we can help organisations identify weaknesses, remove unnecessary complexity and build infrastructure that supports both security and business continuity.

Planning a network transformation or datacentre move? Talk to ANSecurity about how we can help you build resilience into your infrastructure.