The IEC 61850 standard has become the backbone of substation automation, allowing for the first time interoperation between protection, measurement and control devices from different manufacturers on the same Ethernet local area network, station or process bus. This network is duplicated in substations that require a very high availability. Interoperability requires that all devices use the same redundancy concept. IEC 61850 now specifies a network redundancy that fulfills the requirements of substation automation, for the station bus as well as for the process bus.