Special Edition Using TCP/IP, Second Edition

Summary

Data exchange between computers is controlled by a timeout value set on the sending computer. This value is determined by measuring the time taken to complete one full cycle of send and acknowledgement receipt. A weighted average of cycle times is called a round trip time or RTT. This weighted average method, also called adaptive retransmission algorithm, ensures that the timeout value is not modified drastically but is implemented as a slight change. However, the adaptive retransmission algorithm does not help in calculating accurate RTT values when retransmission of segments occurs. To compute an accurate RTT value, the Karn’s algorithm and the timer backoff technique is adopted. This strategy can be used to compute accurate RTT values ...