How utilities can build resilient mission-critical OT networks

Operational technology (OT) networks are the unsung heroes of modern power grids, working behind the scenes to help utilities deliver safe and reliable electricity services that comply with industry and government regulations.

Mission-critical applications across the grid rely on OT networks to provide continuous, deterministic and secure connectivity. Network outages must be avoided because they can disrupt services and produce immediate physical, economic and public safety consequences.

But the risk of outages keeps growing. Power utilities are heaping pressure on their OT networks by adopting data-intensive digital applications. At the same time, OT networks are becoming increasingly attractive targets for attacks by malicious actors. Utilities need modern networks that can keep their mission-critical OT applications up and running as demands and threats evolve.

OT applications present tough networking challenges

Understanding the connectivity challenges that come with OT and SCADA applications is an important first step. These applications have much more stringent network performance and security requirements than IT applications do, including consistently low latency, synchronized timing, and assured delivery of control and protection traffic. 

Today, utilities are introducing digital applications such as fiber sensing, remote operations, IEC 61850 automation, analytics and real-time control. It’s becoming clear that their legacy networks can’t support these applications. Many of these networks were built to provide reliable connectivity for specific applications. As a result, utilities have siloed networks that are expensive to operate and difficult to scale.

An April 2026 report by IDC highlights the key connectivity challenges facing power utilities and other mission-critical operators as they modernize their operations. A survey of 751 respondents across regulated industries reveals that the top challenges include technology procurement and lifecycle management, facilitating technology upgrades and application deployments, aligning technology choices with business requirements and advancing IT/OT convergence.

Regulators and the public are also pressuring utilities to make their OT networks more resilient and secure. This means adding capabilities that will ensure adherence to OT-specific standards that focus on factors such as availability and risk reduction. According to the IDC report, the top three OT security concerns across regulated industries are downtime and disruption caused by cyberattacks, threat detection and anomaly monitoring, and visibility into OT and SCADA devices.

The case for wide-area OT networks

In response to these challenges, utilities are seeking to build OT-specific wide-area networks (WANs). With modern IP/MPLS, optical and WAN technologies, they can meet the strict connectivity, capacity and latency demands of OT environments that combine digital and legacy applications and systems. This means they can support high-value use cases such as integrating distributed energy resources (DERs) and automating intelligent electronic device (IED) operations. 

When modern IP/MPLS WANs are designed for OT demands, they can become valuable strategic assets that make grid operations more resilient and sustainable. Utilities can benefit from OT-specific IP/MPLS WANs in several key ways, including:

• Predictable, deterministic performance enabled by capabilities such as bounded latency, minimal packet loss and consistent performance for control, protection and signaling traffic.
• Stronger cybersecurity protection through segmentation, isolation and controlled network access, which reduce risk and ensure compliance with OT regulations. 
• High availability and millisecond recovery enabled through automated protection and path diversity, which allow OT networks to maintain continuous operation when failures occur.
• Simpler, more agile operations enabled by replacing many legacy systems with one converged network that meets the connectivity needs of all OT applications.
• Easier integration of new power substation sites, DERs and data centers enabled by the inherent flexibility of IP/MPLS and segment routing technologies.
• Lower total cost of ownership (TCO) enabled by a future-proof modern network architecture that supports wide-reaching automation and better visibility.

Key OT network technology enablers

Of course, these benefits are enabled by emerging and evolving technologies. IDC highlights several technology trends that are transforming OT WAN design and operation, including:

• Intelligent routing and automated resilience powered by IP/MPLS and segment routing platforms that enable automatic failure recovery.
• Converged IP/optical transport, which simplifies the network to speed up recovery times, reduce cost and boost resilience.
• Deterministic transport for OT traffic, including the ability to prioritize and create dedicated paths for time-sensitive flows. 
• OT-specific cybersecurity measures that emphasize capabilities such as network segmentation and controlled OT interconnection.
• End-to-end visibility and assurance enabled by capabilities such as telemetry, monitoring and analytics.
• Disruption-free modernization enabled through phased migration and continuing support for essential legacy systems.

It’s time to embrace IP/MPLS and optical WANs for OT

Mission-critical OT networks have a direct impact on the resilience, safety and efficiency of electrical grids. As utilities digitalize and interconnect more of their OT systems, they will need WAN solutions that can support these systems with greatly improved reliability, performance and cybersecurity. 

Utilities can take advantage of advances in IP routing, MPLS transport and optical networking to design and build WANs that make it easier and more economical to address the stringent requirements of OT systems. By deploying the right solutions now, they will be well positioned to keep pace with the growing expectations of regulators and the public—and fight off new cyber threats—with services backed by resilient, secure OT networks.

Find out more 

Read the full IDC report to find out more about the growing importance of resilient mission-critical OT WANs and how Nokia IP/MPLS, optical and network automation solutions can help you deliver safer, more reliable and more sustainable electrical services.