Operational technology (OT) networks come with their own unique set of challenges when trying to diagnose network problems. Unlike IT networks, factors like device communication frequency and bandwidth usage often take on increased importance in OT networks.
In the video below, Marty the OT Guy shares three tips for using Nozomi Networks products to monitor OT networks and quickly diagnose issues.
1. Identifying Network Retransmissions
The first tip is to monitor network retransmissions. Nozomi Networks appliances deployed in the network can detect retransmissions and trigger alerts when they exceed a defined threshold. For example, you could set up an alert if retransmissions on a critical link exceed 10%.
Retransmissions often indicate a problem with network hardware or an underlying issue with the communication medium. In one case, the Nozomi Networks platform helped a customer diagnose excessive retransmissions that turned out to be caused by cows rubbing up against a satellite dish and knocking it out of alignment! Monitoring retransmissions can provide an early warning of degrading network performance.
2. Monitoring Network Throughput Over Time
The second tip is to monitor network throughput over time. Nozomi Networks can track throughput on links over a specified time period. This allows you to define upper and lower bounds for a link's expected throughput and trigger alerts if it falls outside these thresholds. Unusually high or low throughput could signify a problem like a failing device or unplanned new traffic. Again, this provides insight into network behavior changes that might otherwise fly under the radar.
3. Detecting When Devices Stop Communicating
The final tip is to detect when OT devices stop communicating for an unexpected period of time. Since many OT devices communicate regularly, you can set up alerts if they do not communicate for a defined interval. For example, if you have a 12-hour compliance reporting requirement, you may want to detect a loss of communication after 4 hours. This gives you 8 hours to diagnose and address the issue before running afoul of compliance rules.
Monitoring network metrics like retransmissions, throughput, and device communications can provide unique visibility into OT network health. The Nozomi Networks platform make it easy to set up alerts and visualizations based on these metrics.
Diagnosing issues quickly is critical to avoid disruptions and maintain regulatory compliance. Approaches that leverage understanding of OT network patterns are key to troubleshooting problems efficiently. Leveraging these tips and the capabilities of the Nozomi Networks platform makes meeting the monitoring and reliability needs common in industrial environments a whole lot easier.