OT Glossary

In OT, this often means a device or software that connects and translates between different networks or protocols. For example, a protocol gateway might connect a Modbus device to a Profibus network, translating data so both sides understand. Or a gateway could link an isolated control network to a plant DMZ network (with tight security controls). Essentially, whenever two parts of the system that “speak different languages” need to communicate, a gateway is the intermediary that makes it possible (while ideally keeping things secure and compatible).

Generic object-oriented substation event protocol

A communication model part of the IEC 61850 standard (power systems). GOOSE messages are a mechanism for very fast, event-driven communication in electrical substations (for example, to trip breakers or signal alarms). They are multicast messages that can convey a change of state (like “Breaker open!”) with extremely low latency, replacing old hard-wired inter-relays. While this term is power-industry-specific, it’s good to know since modern substations now use GOOSE over Ethernet to react to faults in milliseconds.

Opposite of Brownfield. It describes a new project or facility built from scratch, on a metaphorical “green field” with no constraints from legacy equipment. A greenfield ICS deployment can design security and modern architectures in from the start (a luxury not always present in brownfield sites). For example, a brand-new factory with all new control systems and network infrastructure is a greenfield deployment, and the engineers have free rein to choose the latest technologies and best practices.