Understanding ARS (Automatic Repeat Request) in TCP

ARS stands for "Automatic Repeat Request" and it's a feature in TCP (Transmission Control Protocol) that allows a sender to automatically retransmit lost or corrupted packets.

When a sender transmits data over the network, it assumes that the receiver has received all the packets correctly. However, in some cases, packets may be lost or corrupted during transmission due to various reasons such as network congestion, packet loss, or interference. In such cases, the receiver might not receive all the packets correctly, and the sender would need to retransmit the lost or corrupted packets.

ARS helps to automate this process by allowing the sender to automatically retransmit lost or corrupted packets without requiring any explicit acknowledgement from the receiver. The sender monitors the acknowledgement messages received from the receiver and detects when a packet has not been acknowledged. If a packet is not acknowledged, the sender automatically retransmits that packet.

ARS is useful in unreliable networks where packet loss is common, such as in wireless networks or over long distances. It helps to improve the reliability of data transmission and reduce the likelihood of errors due to lost or corrupted packets.