What does GOOSE stand for and what does it do?

GOOSE stands for Generic object oriented system-wide events.
GOOSE aims to replace the conventional hard-wired logic necessary for intra-relay coordination with station-bus communications. Upon detecting an event, the IED (s) use a multi-cast transmission to notify those devices that have registered to receive the data. The performance requirements are stringent, no more than 4 ms is allowed to elapse from the time an event occurs to the time of message transmission.
The number of IEDs, the network topology and the type of event will all contribute to the amount of data that will be generated after an event. Collisions are quite possible in an Ethernet network in this scenario, so the GOOSE messages are re-transmitted multiple times by each IED. Three LAN configurations are able to deliver 100 messages within 4 ms, they are 10 Mb switched hub, 100 Mb shared hub, and a 100 Mb switched hub.