Repeater is a device that connects network lines and is often used for two-way forwarding of physical signals between two network nodes.The repeater mainly performs the functions of the physical layer. It is responsible for bit-by-bit information transfer on the physical layer of the two nodes and completes the functions of signal replication, adjustment and amplification, so as to extend the length of the network.Due to the loss, the signal power transmitted on the line will gradually attenuate. When the attenuation reaches a certain degree, the signal will be distorted, which will lead to reception error.Repeaters are designed to solve this problem.It completes the connection of the physical circuit, amplifies the attenuated signal, and remains the same as the original data.In general, the two ends of a repeater are connected to the same media, but some Repeaters can also transfer different media.In theory the use of Repeaters is infinite and the network can therefore be extended indefinitely.In fact, this is not possible, because the network standard has specified the delay range of signals, Repeaters can only perform effective work within the specified range, otherwise it will cause network failure.