Motivation
In any communication protocol based on automatic repeat request for error control, the receiver must acknowledge received packets. If the transmitter does not receive an acknowledgment within a reasonable time, it re-sends the data.
A transmitter that does not hear an acknowledgment cannot know if the receiver actually received the packet; it may be that it was lost or damaged in transmission. If error detection reveals corruption, the packet will be ignored by the receiver and no acknowledgement will be sent. Similarly, the receiver is usually uncertain about whether its acknowledgements are being received. It may be that an acknowledgment was sent, but was lost or corrupted in the transmission medium. In this case, the receiver must acknowledge the retransmission to prevent the data being continually resent, but must otherwise ignore it.
Read more about this topic: Sliding Window Protocol
Famous quotes containing the word motivation:
“Self-determination has to mean that the leader is your individual gut, and heart, and mind or we’re talking about power, again, and its rather well-known impurities. Who is really going to care whether you live or die and who is going to know the most intimate motivation for your laughter and your tears is the only person to be trusted to speak for you and to decide what you will or will not do.”
—June Jordan (b. 1939)