What does repeater mean? Brief introduction of repeater.

RP repeater is a device connecting network lines, which is often used for two-way forwarding of physical signals between two network nodes. Repeater is the simplest network interconnection equipment, which mainly completes the function of physical layer, and is responsible for transmitting information bit by bit on the physical layer of two nodes, and completing the functions of signal replication, adjustment and amplification, thus prolonging the length of the network. Because of the loss, the signal power transmitted on the line will gradually decay, which will cause signal distortion to some extent, thus leading to reception errors. Repeater is designed to solve this problem. It completes the connection of physical lines, amplifies the attenuated signal and keeps it the same as the original data. In general, both ends of the repeater are connected to the same medium, but some repeaters can also complete the transmission of different media. Theoretically, the use of repeaters is unlimited, so the network can be extended indefinitely. In fact, this is impossible, because the network standard stipulates the signal delay range, and the repeater can only work effectively within this specified range, otherwise it will cause network failure. Repeater works in the physical layer of OSI and is the center of all nodes on LAN. Its function is to amplify signals, compensate signal attenuation and support long-distance communication. The advantage is to expand the communication distance, but at the cost of increasing some store-and-forward delay. The maximum number of nodes is increased. Each network segment can use different communication rates. And the reliability is improved. When a network fails, it usually only affects a single network segment. The performance has been improved. The disadvantage is that the repeater regenerates (recovers) the received attenuated signal to the state when it was sent, and forwards it, which increases the delay. The MAC sublayer of CAN bus has no flow control function. When the network load is heavy, it may overflow due to insufficient buffer storage space in the repeater, resulting in frame loss. If the repeater fails, it will affect the work of two adjacent subnets.