Abstract:
The present invention discloses a method of transmitting time-critical messages in an OSI layer 2 network tunnel from an IED in a first substation to an IED in a second substation over a WAN, wherein each of the first and second substation comprises an edge IED and is associated with a substation LAN, wherein each of the time-critical messages comprises message parameters. The method comprises the steps of: a) creating a translation table comprising corresponding values of the message parameters, between the LANs and the WAN, b) defining a virtual IED model in the second substation using the translated values of the message parameters, to impersonate the IED of the first substation, c) translating the message parameters according to the translation table, d) forwarding the time-critical messages from the IED in the first substation to the WAN, and e) receiving the time-critical messages by the IED of the second substation from the WAN.