Cheap Supplementary Link-8 is an inexpensive alternative to popular full-speed modems, such as the CCITT V.34 or V.90, for applications that require low speed data transmission. This device supports up to 8 Kbps, with optional support for higher speeds of 14.4 Kbps or up to 56 Kbps modems. It was designed primarily as a low-cost remote monitoring and control device, used in applications such as Internet of Things (IoT) networks, smart home, remote security monitoring, as well as medical and industrial control. Cheap Supplementary Link-8 is a low-cost modem device that provides an economical alternative to traditional full-speed modems. It is compatible with most operating systems, and is easy to install and configure. The device is powered by an external AC/DC adapter and includes a variety of interfaces to connect to an Ethernet port or other data communication systems. It has a compact, lightweight design with a small footprint, and consumes low power, making it well suited for embedded applications. The device supports link-level protocols such as TCP/IP, L2TP, Syslog, and Modbus over Ethernet, allowing it to be used in a variety of networks. It also supports link-level encryption and authentication for added security. The device also features diagnostic LEDs to provide status information, such as power, carrier detection, and modem error conditions. In summary, Cheap Supplementary Link-8 is an ideal solution for applications that need a low-cost, reliable modem for data communication. It is easy to install and configure, and provides a secure and reliable connection for remote monitoring, control, and data transmission.