TCP/IP Guide

TCP Connection Management and Problem Handling

Once both of the devices in a TCP connection have completed connection setup and have entered the ESTABLISHED state, the TCP software is in its normal operating mode. The TCP software will package bytes of data into segments for transmission using the mechanisms described in Chapter 48. TCP will use the sliding windows scheme to control segment size and to provide flow control, congestion handling, and retransmissions as needed.

Once in the sliding windows mode, both devices can remain there indefinitely. Some TCP connections can be very long-lived—in fact, some users maintain certain connections like Telnet sessions for hours or even days at a time. The following two circumstances can cause a connection ...