- Oct 13, 2017 -
Repeater is the simplest and cheapest interconnection device used to extend network distance in the LAN environment, operating in the physical layer of OSI, the repeater has the function of amplifying and reproducing the signal on the line.
Repeater is a kind of device connecting network line, which is used for bidirectional forwarding of physical signals between two network nodes. The 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 the duplication, the adjustment and the enlargement function, in order to lengthen the network the length. Because of the loss, the signal power transmitted on the line will gradually decay, the attenuation to a certain extent will cause the signal distortion, so will lead to receive errors. The repeater is designed to solve this problem. It completes the connection of the physical wiring, amplifies the attenuation signal and remains the same as the original data. In general, the two ends of the repeater are connected to the same media, but some repeaters can also complete different media transfer work. Theoretically speaking, the use of repeaters is unlimited and the network can be extended indefinitely. In fact, this is not possible, because the network standard in the delay range of the signal to make specific provisions, the repeater can only within the scope of effective work, otherwise it will cause network failure.
The communication distance is enlarged, but the cost is increased by some store forwarding delay.
Increases the maximum number of nodes.
Each network segment can use different communication rates.
Increased reliability. When a network failure occurs, it generally affects only individual network segments.
Due to the repeater's regeneration (recovery) of the signal received by the attenuation to the state of the sending, and forwarding out, increased delay.
The MAC 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 of the buffer in the repeater, resulting in a frame loss phenomenon.
If the repeater fails, it will have an impact on the work of the neighboring two subnets.