What is GOOSE?
GOOSE stands for Generic Object Oriented Substation Event and is a Real-time communication protocol within IEC 61850. It is used to transmit critical events at very high speed between devices in a substation, such as protection relays, measurement units and switches.
GOOSE delivers sub-millisecond response times and is widely used in digital high-voltage substations and industrial power distribution.
🧠 How does GOOSE work?
- GOOSE sends messages via Ethernet multicast – without TCP/IP
- Each message contains data objects (e.g. switch status, current trip, alarm signal)
- A GOOSE message is transmitted repeatedly at decreasing intervals to ensure reliability
- GOOSE is event-driven: messages are sent when state changes occur
- Operates at Layer 2 of the OSI model with short response times (typically <4 ms)
GOOSE is vendor-independent and standardised within IEC 61850.
🏭 Application of GOOSE in industrial networks
- Trip lines between protection relays for current, voltage or earth fault detection
- Real-time communication between IEDs (Intelligent Electronic Devices) in substations
- Direct control of circuit breakers without SCADA involvement
- Rapid status communication of generators, transformers or disconnectors
- Industrial power distribution in sectors such as oil, chemicals, metals and data centres
GOOSE replaces traditional hardwired signalling and reduces cabling, error rates and response time.
🔍 GOOSE vs. MMS vs. SV
| Protocol | Purpose | Transport layer | Use |
|---|---|---|---|
| GOOSE | Event-based status messages | Ethernet (Layer 2) | Trip, alarms, status |
| MMS | Data exchange, SCADA integration | TCP/IP (Layer 4) | Logging, configuration, SCADA |
| SV | Sampled analog values | Ethernet multicast | Continuous measurements such as current and voltage |
🔐 Security aspects
- GOOSE messages are neither encrypted nor authenticated
- Secure via VLAN, ACL, Port Security and Firewall
- Use TAP or SPAN for passive inspection of GOOSE traffic
- Monitor GOOSE events and duplicates via SIEM or specialist GOOSE analysis tools
- Protect the configuration via RBAC and ensure physical network separation
In an unprotected network, GOOSE messages can be manipulated with potentially serious consequences (e.g. unwanted tripping).
📌 In summary
GOOSE is a fast and reliable event protocol within IEC 61850, designed for real-time communication in substations and industrial energy networks. Thanks to its speed and simplicity, it replaces conventional signal cables and enables flexible energy automation.