Glossary · Automation software engineering and architecture
Protocol stack
Also known as: Network stack, Communication stack
German: Protokollstapel
In communication systems, a protocol stack is a set of layered protocols and the software that implements them, in which each layer uses the services of the layer below and offers services to the layer above.
- Software engineering
In one sentence
A protocol stack is a set of layered communication protocols and their implementation, each layer serving the one above.
Example
The field device's PROFINET protocol stack runs on the communication processor and passes cyclic I/O data to the application firmware through a defined interface.
How it applies
- Engineering: Device makers often license a certified stack for industrial Ethernet or OPC UA rather than implementing it. The stack's version and configuration then become part of the product's configuration and conformance testing.
- Security: Vulnerabilities in widely used stacks affect many products at once; vendors must track stack updates as part of Patch management.
- Documentation: Technical data should name the supported protocols, versions and conformance classes. Security documentation should list the services the stack exposes.
Protocol stack vs. protocol
A Protocol (communication) is the set of rules for exchanging messages. A protocol stack is the layered combination of several protocols, and often the software implementing them.