Now the sender has despatched the packets zero, one, two and three. Assume that we’ve plenty of sequence numbers, for the sake of explanation. In the diagram below the sender’s window has a size of four, or Go Back-4. Now we will understand how Go Back-N actually works with the help of an example. If window size is one, the protocol reduces to stop-and -wait protocol. In order to implement pipelining, the window size should always be greater than one. If we say the protocol is GB-4, then WS = 4. The sender’s window is of size N and the receiver’s window size is always one. This protocol is used for flow control in networking and is a part of the data-link layer.
The Go Back-N ARQ or Go Back Automatic Repeat Request is a way to implement sliding window protocol.
