3.1 Techniques and Protocols

When combining the best of both worlds (IT and OT), there are a couple of techniques that can be considered best-practice.

Open-Source

Open-Source is source code that is made available for free for possible modification and redistribution. The concept is well established in the field of IT. Some example of Open-Source projects are:

• Linux is running on all top 500 supercomputer in the world
• Kubernetes and TensorFlow are the central software for Microservice architecture
• f-prime by NASA which controls the Mars helicopter Ingenuity

Open Source as a concept is also transferring into OT and IIoT, as Open-Source software is neutral and therefore enables a shared infrastructure between competitors.

If you are interested, you can take a look at our blog article: Open-Source in Industrial IoT: an open and robust infrastructure instead of reinventing the wheel

Unified Namespace / MQTT / Sparkplug B

Unified Namespace is a different name for event-driven architecture tailored to manufacturing by using MQTT as a central message broker. Sparkplug B is another layer on top of MQTT.

More information on this can be found in the article to MQTT and Unified Namespace

Demilitarized zones

There are several industry-wide standards, established by leading companies and organizations, that recommend a segmentation of the business network system from the plant networks.

Cisco, Rockwell Automation, VDMA, and more, are recommending to create a Demilitarized Zone (DMZ), sometimes also referred to as a perimeter network. It is a common approach used in general IT-network security but is still in an early adoption phase for IIoT devices.

More information can be found in our blog article: Why are our networks open by default and how do I protect my valuable industrial assets?

Protocols

Protocols are sets of rules that ensure communication can happen without any issues. They define synchronization and syntax of communication, so every message has an exact way of being interpreted in a certain protocol.

There are quite a bit of examples of protocols frequently used in IIoT architectures:

• Coming from IT: MQTT, which as described above is an example of event driven architecture
• Coming from IT: Apache Kafka, which also is event driven architecture with some different features
• Coming from IT: HTTP(S)/REST, which follows server-client architecture and is responsible for a lot of web API infrastucture
• Coming from OT: OPC UA, which follows server-client architecture, which has tons of specifications for all sorts of languages