The IEC 62439 series is applicable to high-availability automation networks based on the ISO/IEC/IEEE 8802-3 (IEEE 802.3) (Ethernet) technology. This part of the IEC 62439 series specifies a recovery protocol based on a ring topology@ designed to react deterministically on a single failure of an inter-switch link or switch in the network@ under the control of a dedicated media redundancy manager node.