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The TCP/IP Guide  9  TCP/IP Lower-Layer (Interface, Internet and Transport) Protocols (OSI Layers 2, 3 and 4)       9  TCP/IP Transport Layer Protocols            9  Transmission Control Protocol (TCP) and User Datagram Protocol (UDP)                 9  TCP/IP Transmission Control Protocol (TCP)                      9  TCP Reliability and Flow Control Features and Protocol Modifications

TCP Segment Retransmission Timers and the Retransmission Queue 1 2 3 4 TCP Adaptive Retransmission and Retransmission Timer Calculations

There Is No Ideal Answer

Since TCP doesn't know whether these other segments showed up, it cannot know which method is better. It must simply make an “executive decision” to use one approach or the other, and hope for the best. In the example of the previous topic, as shown in Figure 223, I demonstrated the “conservative” approach—only the lost segment of the file was retransmitted. In contrast, Figure 224 shows the “aggressive” approach to retransmission.

TCP Segment Retransmission Timers and the Retransmission Queue 1 2 3 4 TCP Adaptive Retransmission and Retransmission Timer Calculations