Information and communications technologies (ICT) have been paramount in the evolution of the electricity sector. They are essential to maintaining high stability and reliability standards in the new context of Active Distribution Networks (ADN). This article reviews different communication technologies for this type of network. The main characteristics, advantages, disadvantages, related software, manufacturers, and applications are presented. The review is focused on wired communications protocols that support the operation of supervisory control and data acquisition (SCADA) systems, such as Modbus, DNP3, IEC60870, and IEC61850. Wired IoT (Internet Of Things) technologies are also considered since they are the basis for cyber-physical systems such as UART, SPI, I2C, RS232, RS485, CANBUS, PLC, and Ethernet.