Industrial digitalization doesn’t happen overnight. It slowly builds until once-adequate networks quietly become the constraint holding everything else back. Without a forward-looking, highly scalable foundation, legacy hardware will inevitably bottleneck future digital innovation. As OT networks transform from background infrastructure into the critical foundation powering industrial operations, it requires getting three things right. Those are reliability and performance, security, and visibility. In this article, we are going to focus on the most immediate challenge: delivering the reliability and performance required to handle the exponential growth of data in digitalized OT networks.
Building reliable, high-performance operations requires a network design that is founded on four critical capabilities: expanding backbone capacity, converging deterministic networking, extending Ethernet reach, and high-power edge connectivity. In the following sections, we will examine each of these four challenges and explore solutions network operators can leverage to futureproof their operations for a digitalized tomorrow.
Challenge 1: Legacy Backbone Capacity Meets New Data Demands
The situation
Yesterday's OT networks were built for lightweight, predictable control traffic. Today, they must also carry machine vision data, condition monitoring telemetry, and analytics feeds. Machine vision is by far the biggest bandwidth strain. Inspection cameras stream massive, raw, uncompressed image files to ensure maximum accuracy. Add that up across every camera on a production line, layer in sensor, PLC, and SCADA traffic, and a legacy backbone quickly runs out of headroom. This scenario illustrates that high-bandwidth infrastructure is non-negotiable for modern OT networks.
Design considerations
The first logical step is to increase bandwidth by upgrading to Gigabit or 10Gigabit switches. While it may sound straightforward, how you distribute this bandwidth across the network architecture matters just as much as raw throughput. A common mistake is upgrading the core while leaving the distribution layer unchanged, creating a bandwidth funnel at the edge, where most of your field data aggregates. For imaging and analytics workloads, a 10GbE core paired with 1GbE distribution layer is sufficient, while 10GbE may be required when several high-volume traffic sources aggregate at one switch. Modular switches play a useful role here. With various media, port count, and power modules, operators can quickly adjust to real-time network demands.
Just as important as raw performance is redundancy. Traditional STP-based recovery can take up to 30 seconds. In an OT environment, this is long enough to cause serious production disruptions and flawed output. Prioritizing industrial ring protocols capable of sub-50 ms recovery minimizes downtime and limits any potential impact. For optimal reliability, the topology should also be designed so that no single link failure can disrupt time-sensitive control traffic.
A futureproof backbone is more than just raw speed; it requires an architecture that prevents distribution bottlenecks, supports hardware flexibility, and enforces ultra-reliable OT redundancy.
Challenge 2: Mixed-criticality OT Traffic on a Shared Network
The situation
In modern production facilities, two fundamentally different types of data are moving over the same network: time-critical control data that demands microsecond-level precision and an unpredictable, bandwidth-heavy flood of surveillance and sensor data. Historically, engineers managed these data streams through physical segregation. In a highly digitalized environment, this approach is no longer workable and quickly turns into a cabling nightmare filled with multiplied hardware costs and unmanageable infrastructure.
Design considerations
Converging both data types to run over the same connection offers the most practical solution. However, this raises a new challenge. How can you ensure that bulk data does not interfere with critical control data? Standard Quality of Service (QoS) mechanisms are best-effort and offer no deterministic guarantee for control traffic. Even with the best-configured QoS policy, a sudden burst of surveillance data could delay critical control frames in the queue. Adopting time-sensitive networking (TSN) technology circumvents these limitations. TSN uses time-aware scheduling to create synchronized, exclusive transmission windows for time-critical frames. This enables true deterministic delivery regardless of concurrent load, making it highly valuable where your shared switching infrastructure converges, such as at the cell and distribution levels. Keep in mind that TSN is a suite of standards, not a single implementation, and vendor conformance varies. Before implementing TSN in your infrastructure, it is important to verify that end devices and switches have been thoroughly tested for interoperability.
Converging critical control and other bulk data onto the same network offers a practical solution to the problem of expansion complexity, but raises new data segregation challenges. TSN technology creates a deterministic environment that ensures critical control data is delivered predictably, no matter the traffic load.
Challenge 3: Extending Ethernet Reach to Field-level Devices
The situation
Digitalization promises many enticing outcomes for plant operators, such as predictive maintenance, higher efficiency, and better analytics. In practice, these benefits often collide with the harsh reality on the plant floor, where many critical field instruments still run on legacy analog loops or slow fieldbus protocols. Replacing the entire field installation with Ethernet-based devices would require crippling downtime and a staggering investment that would be a non-starter for most operators.
Design considerations
The industry has developed two complementary solutions to address this issue by extending Ethernet connectivity to the field level: Single-pair Ethernet (SPE) and Ethernet-APL. Both are Ethernet standards that leverage a single pair of wires but target different field applications.
Single-pair Ethernet (SPE) is the general-purpose option for industrial automation, carrying data and power up to 1,000 meters at speeds up to 10 Mbps. Ethernet-APL is an enhanced physical layer for SPE to be used in hazardous process environments and can reach up to 200 meters.
By deploying SPE and Ethernet-APL-capable switches in strategically placed junction boxes, operators can aggregate and send field device data over Ethernet to the control layer without having to conduct an extensive equipment overhaul. The two-wire design of SPE and Ethernet-APL also means reduced cabling cost and complexity, and the potential to repurpose existing single-pair non-Ethernet field wires for legacy 4–20 mA or HART analog loops.
Bringing Ethernet connectivity to the edge using Single-pair Ethernet (SPE) and Ethernet-APL bridges the control and field layers and digitalizes your operations without requiring extensive overhauls and high capital expenditure (CAPEX).
Challenge 4: Powering Edge Devices Where Infrastructure Is Sparse
The situation
When integrating IP cameras, wireless access points, and industrial IoT nodes in your edge installation, the likelihood of having ready access to a power source is low. Running separate power cabling to each location is expensive and slow. In more complex vertical structures or outdoor installations, power planning is a massive project in its own right. This issue becomes even more pressing when scaling up your operations and introducing more devices into your OT network infrastructure.
Design considerations
Power over Ethernet (PoE) provides a practical means to circumvent power access constraints. IEEE 802.3bt high-power PoE delivers up to 90 W per port over the same Ethernet cable carrying data, making it ideal for digitalized environments with many high-draw edge devices. Deploying high-capacity PoE switches simplifies the deployment of powered devices and cuts down on cabling costs and complexity. An important caveat when planning PoE infrastructure is that a PoE switch’s power budget, not the per-port output, decides the number of devices it can power. To ensure a stable power supply under any condition, size your total power budget against your actual PoE device mix at worst-case draw.
When choosing PoE switches, don’t overlook environmental resilience. These switches sit near the edge devices they power, which are often operating in demanding environmental conditions. Prioritize industrial-grade switches that offer wide operating temperature ranges and high EMC. Lastly, consider power redundancy and availability. The capability of your PoE switches to connect to a redundant external power supply (EPS) is critical for sustaining power output to your surveillance and critical communication nodes during a main power failure.
High-power PoE takes power scarcity out of the equation by providing power and data to edge devices over the same wire, simplifying installation and cutting cabling costs.
Completing the Triad: The Final Pieces of a Futureproof Network
Building a reliable, high-performing network is only the first critical step toward achieving full digitalization. While each of the capabilities we discussed in this article fundamentally transforms your network and allows you to break silos and move more data, it also leads to some unavoidable consequences.
Integrating legacy field devices into the digital domain increases the attack surface against your network. A simple security breach now puts your machinery and operations at risk. Cybersecurity must be an architectural cornerstone of your digitalization plan. Hardening devices according to IEC 62443-4-2 requirements, implementing strict zone segmentation, and passive monitoring are only the tip of the iceberg.
The larger scale of your network means it becomes more difficult to manage. Without centralized visibility of your operations, issues like firmware gaps, link degradation, and configuration drift go unnoticed until it’s too late. The ability to conduct real-time monitoring and troubleshooting is essential to maintain full control over your plant network.
As your network evolves into the nerve center of your operations, performance, reliability, security, and visibility must come together as a single foundation to upgrade your operations for tomorrow’s digital landscape.
Moxa’s Solutions
Building a futureproof network begins with creating a robust, scalable foundation. Moxa’s industrial networking solutions provide the tools to help you seamlessly digitalize your operations, including high-capacity switching, Ethernet field extension, TSN determinism, and high-power PoE.
→ Explore Moxa’s Futureproof Industrial Network Solutions