About Sheffield Teaching Hospitals
Sheffield Teaching Hospitals (STH) is one of the largest NHS trusts in the UK, delivering specialist, community, and acute care across multiple major sites, including the Royal Hallamshire and Northern General Hospitals.
When legacy core and datacentre infrastructure approached end of life, the trust needed a partner it could rely on to modernise its most business-critical networks and build a secure, scalable foundation for the future. Despite being a relatively small specialist consultancy at the time, EDNX was appointed to lead two of STH’s most critical infrastructure programmes – a decision rooted in years of proven expertise and the confidence the trust placed in the team’s ability to deliver under pressure.
Key deliverables
End-to-end delivery covering design, proof of concept, and phased implementation
SD-Access (SDA) design and deployment across the campus local area network (LAN)
Architectural planning for migration from ageing core switches at Northern General and Royal Hallamshire
Cisco Application Centric Infrastructure (ACI) design and datacentre implementation at reduced scale
Extensive testing, resilience validation, and failover modelling
Pandemic-era project execution, with logistics planned around NHS site restrictions
Ongoing consultancy, including Cisco Identity Services Engine (ISE) upgrades and strategic network guidance
STH’s challenge
EDNX’s relationship with STH runs deep. Long before the company was founded in 2018, founders Dave and Wojtek had worked with the trust as network architects for several years, supporting a number of major initiatives. When STH began planning significant LAN and datacentre refresh programmes in 2020, it naturally turned to the engineers it already knew, trusted, and had seen deliver reliably in high-pressure environments.
The trust faced several critical infrastructure challenges. Core LAN hardware across two of its largest hospitals had reached end of life, while ageing Nexus switches in the datacentre were beginning to limit future growth. At the same time, the organisation needed stronger security, simpler policy control, and improved network segmentation to keep pace with modern clinical demands. Underpinning all of this was the requirement for a scalable infrastructure capable of supporting rapidly evolving clinical systems.
Without decisive intervention, STH risked operating unsupported infrastructure, weakening resilience, and increasing cybersecurity exposure – all of which posed significant operational risk to day-to-day healthcare services. But this was no small feat. Beyond operating in a busy clinical environment with no room for downtime, EDNX was also grappling with pandemic-induced restrictions that placed logistics under pressure.
Our solution
EDNX approached the programme with a methodical, collaborative strategy designed to minimise risk and give STH complete confidence at every stage. Rather than moving directly to a trust-wide rollout, the initial focus was on detailed architectural design, proof of concept, and controlled, smaller-scale deployments of both SD-Access (LAN) and ACI (datacentre) technologies.
Working closely with STH’s technical teams, EDNX produced full network designs and clearly defined migration methodologies for both environments. These designs were then demonstrated through SDA and ACI implementations at reduced scale across the campuses and datacentre. This allowed the trust to explore the technologies in live environments, validate resilience and operational processes, test failover scenarios, and fully understand the implications of migration – all without committing to immediate mass deployment.
This phased approach provided transparency and assurance, enabling stakeholders to assess the platforms, refine operational processes, and make informed decisions about wider adoption. Based on the success of these deployments and the outlined migration strategy, STH elected to progress with broader rollout activity from 2021 onwards, with elements of the programme continuing to evolve today.
Once the approach had been proven at a smaller scale, EDNX supported STH with a clear roadmap for expansion, including:
SD-Access fabric design, validated through campus deployments, alongside a structured methodology for migrating from legacy core switches at Northern General and Royal Hallamshire
ACI fabric design and datacentre implementation, demonstrated at reduced scale, supported by detailed service migration and validation processes to enable phased adoption over time
This approach ensured the trust retained full control over the pace, scope, and timing of rollout, while establishing a modern, policy-driven network architecture ready to scale in line with clinical and operational priorities.
Crucially, much of this work was carried out during the height of the COVID-19 pandemic. With lockdowns and strict NHS site controls in place, EDNX carefully coordinated access, testing, and deployment activity around critical clinical services. Despite these constraints, the programme maintained momentum and delivered its objectives without disruption to patient care.
The result
The transformation has given STH a far more resilient, secure, and adaptable network foundation across both its campus and datacentre environments. By moving to SD-Access and ACI, the trust now benefits from a security-centric architecture that brings consistency, control, and long-term flexibility to some of the busiest (and biggest) clinical sites in the region.
The new estate delivers:
Consistent segmentation and policy enforcement across all major hospital sites
A scalable platform capable of supporting future clinical and digital systems
Reduced operational complexity through automation and centralised control
A modern network ready to evolve with the trust’s long-term digital strategy
While elements of the migration programme remain ongoing, the architectural shift is already clear: STH is transitioning towards a next-generation network built to support the pressures, pace, and criticality of modern healthcare delivery.
The relationship between EDNX and STH continues to strengthen too. EDNX now supports ongoing initiatives, including ISE upgrades and advanced consultancy across the trust’s wider network environment – ensuring its infrastructure continues to mature in line with its ambitions.
Reflecting on the programme, Wojtek Siodelski, CTO and founder of EDNX, said:
“Working with STH on both SD-Access and ACI deployments was one of the most challenging projects for EDNX from a technical point of view. It was the first time we had the opportunity to implement advanced technology on such a large scale. Delivering these programmes during strict lockdown added another layer of complexity, but we’re incredibly proud that such a large organisation trusted our specialist team with the full design and deployment. Now, as a bolt-on strategic partner, we’re thrilled to support its ongoing development too.”
