Repeaters extend the communication distance. The maximum number of nodes has been increased. Each network segment can use different communication rates. Improved reliability. When the network fails, it generally only affects individual network segments. The Internet performance is improved.

Due to the influence of transmission line noise, the digital signal or analog signal carrying information can only transmit a limited distance. The function of the repeater is to regenerate and transmit the received signal, thus increasing the distance of signal transmission. It connects two or more network segments of the same network. For example, Ethernet often uses repeaters to extend the cable length of the bus. The maximum length of each segment of standard thin cable Ethernet is 185 meters, and the maximum length can be 5 segments. Therefore, after adding repeaters, the maximum network cable length can be increased to 925 meters. Generally speaking, the network segments at both ends of the repeater are network segments, not subnets.