Emulation of IEC 60870-5-104 Communication in Digital Secondary Substations

This paper describes two methods of emulation of digital secondary substations and their communication to the control center via the IEC 60870-5-104 protocol. The first method describes use of Mininet network emulator, which omits certain minor networking features, but can create the topology very efficiently. The second method describes use of virtual machines, which can be interconnected to achieve the full functionality including router devices and VPN connections. An open source library libIEC60870-5 is used for communication between substations and the control center. The library is analyzed and compared to real traffic provided by Norwegian National Smart Grid Laboratory. Based on found differences, the paper provides information of how to modify the library in order to create messages identical to the real traffic. These messages can be used to verify the substation behavior, or for security penetration testing by creating messages with spoofed temperature or multimeter sensor values.