What's a repeater?

Repeater is the simplest and cheapest interconnect device used to extend the network distance in the LAN environment, operates on the physical layer of OSI, and the repeater has the function of amplifying and regenerating the signal on the line.

The Repeater (RP repeater) is a device connecting the network line, which is often used in bidirectional forwarding of physical signals between two network nodes. Repeater is the simplest network interconnection equipment, mainly completes the physical layer function, is responsible for the two nodes physical layer to pass the information, completes the signal duplication, the adjustment and the amplification function, thus lengthens the network the length. Because of the loss, the signal power transmission on the line will gradually decay, attenuation to a certain extent will cause signal distortion, which will result in receiving errors. Repeaters are designed to solve this problem. It completes the connection of the physical circuit, amplifies the attenuation signal and maintains the same as the original data. In general, the repeater is connected to the same media at both ends of the relay, but some repeaters can also do different media transfer work. In theory, the use of repeaters is infinite, so the network can be extended indefinitely. In fact, this is not possible, because the network standards in the signal of the delay in the scope of the specific provisions, repeaters can only be effective in this scope of work, otherwise it will cause network failure.

Role

The Repeater (Repeater), which works on the physical layer of OSI, is the center of all nodes on the LAN, and its role is to amplify the signal, compensate for the attenuation of the signal, and support long-distance communication.

Advantages

Increased the communication distance, but at the cost of adding some storage forwarding latency.

The maximum number of nodes has been added.

Different communication rates can be used for each network segment.

Improve the reliability. When a network fails, it generally affects only individual network segments.

Performance has improved.

Disadvantages

The delay is increased due to the repeater's state of receiving the attenuated signal when it is regenerated (restored) to the time it is sent and forwarded out.

The Mac child layer of CAN bus has no flow control function. When the load on the network is heavy, it may overflow due to insufficient storage space in the repeater, resulting in the phenomenon of frame loss.

If the repeater fails, it will have an impact on the work of the two adjacent subnets.