TCP’s flow control mechanism works by allowing the receiver to control the amount of data sent by the sender. The receiver maintains a buffer that stores the received data, and it sends acknowledgments (ACKs) back to the sender to indicate the amount of data it can receive. If the receiver’s buffer is full, it sends a small ACK to slow down the sender’s transmission rate.
The sender monitors the ACKs sent by the receiver and adjusts its transmission rate accordingly. If the sender receives a small ACK, it decreases its transmission rate, and if it receives a large ACK, it increases its transmission rate. This way, the sender can avoid overwhelming the receiver’s buffer and causing packet loss.
TCP’s flow control mechanism is called sliding window flow control, which means that the sender maintains a “window” of the sequence numbers that it is allowed to send. As the receiver sends ACKs, it moves the window forward, allowing the sender to send more data. Sliding window flow control allows TCP to dynamically adjust the rate of data transmission based on the network conditions and capacity of the receiver.
