The repeater works at the physical layer of OSI and is the center of all nodes on the LAN. Its function is to amplify signals, compensate for signal attenuation, and support long-distance communication. Repeater. Working in the physical layer, it only plays the role of extending the transmission distance and is transparent to the high-level protocol. In fact, the network connected by repeaters is equivalent to a larger network composed of the same wire. Repeaters can also connect networks of different transmission media (10Base5 and 10Base2) together, and are often used in the interconnection of the same LAN above the data link layer.