C-10 D30 Line Distance Protection System GE MultilinC.4 GENERIC SUBSTATION EVENT SERVICES: GSSE AND GOOSE APPENDIX CCC.4.5 ETHERNET MAC ADDRESS FOR GSSE/GOOSEEthernet capable devices each contain a unique identifying address called a Media Access Control (MAC) address. Thisaddress cannot be changed and is unique for each Ethernet device produced worldwide. The address is six bytes in lengthand is usually represented as six hexadecimal values (for example, 00 A0 F4 01 02 03). It is used in all Ethernet frames asthe ‘source’ address of the frame. Each Ethernet frame also contains a destination address. The destination address canbe different for each Ethernet frame depending on the intended destination of the frame.A special type of destination address called a multicast address is used when the Ethernet frame can be received by morethan one device. An Ethernet MAC address is multicast when the least significant bit of the first byte is set (for example, 0100 00 00 00 00 is a multicast address).GSSE and GOOSE messages must have multicast destination MAC addresses.By default, the D30 is configured to use an automated multicast MAC scheme. If the D30 destination MAC address settingis not a valid multicast address (that is, the least significant bit of the first byte is not set), the address used as the destina-tion MAC will be the same as the local MAC address, but with the multicast bit set. Thus, if the local MAC address is 00 A0F4 01 02 03, then the destination MAC address will be 01 A0 F4 01 02 03.C.4.6 GSSE ID AND GOOSE ID SETTINGSGSSE messages contain an identifier string used by receiving devices to identify the sender of the message, defined in IEC61850 part 8-1 as GsID. This is a programmable 65-character string. This string should be chosen to provide a descriptivename of the originator of the GSSE message.GOOSE messages contain an identifier string used by receiving devices to identify the sender of the message, defined inIEC 61850 part 8-1 as GoID. This programmable 65-character string should be a descriptive name of the originator of theGOOSE message. GOOSE messages also contain two additional character strings used for identification of the message:DatSet - the name of the associated dataset, and GoCBRef - the reference (name) of the associated GOOSE control block.These strings are automatically populated and interpreted by the D30; no settings are required.