A network topology describes how devices are connected and how data can travel between them. Topology affects reliability, cost, troubleshooting and how failures propagate — important for both IT Ethernet and industrial fieldbuses.
Related: OSI Model | Switches and VLANs | TCP/IP Fundamentals | Modbus RTU | Profibus
| Topology | Structure | Notes |
|---|---|---|
| Mesh | Each device connects to many or all others | High redundancy and fault tolerance; complex and cabling-heavy |
| Star | All devices connect to a central switch or hub | Common on Ethernet; one device failure does not take down others; centre is a single point of failure |
| Ring | Devices form a loop; each links to next | Data circulates; a break can disrupt the ring unless redundancy is designed in |
| Bus | All devices share one backbone channel | Simple; backbone failure affects everyone; common on older serial fieldbuses |
| Hybrid | Combination of two or more topologies | Flexible for large plants (e.g. star access layers tied into a backbone) |
Choice depends on network size, required redundancy, scalability and cost. Industrial serial networks (for example Modbus RTU / Profibus) often favour bus or daisy-chain layouts with strict stub rules; Ethernet plant floors usually use star or hybrid designs around switches.