TCP/IP Guide

TCP Window Size Adjustment and Flow Control

We have seen the importance of the concept of window size to TCP's sliding window mechanism. In a connection between a client and a server, the client tells the server the number of bytes it is willing to receive at one time from the server; this is the client's receive window, which becomes the server's send window. Likewise, the server tells the client how many bytes of data it is willing to take from the client at one time; this is the server's receive window and the client's send window.

The use of these windows is demonstrated in Chapter 48, where we discussed TCP's basic data transfer and acknowledgment mechanism. However, just as the example in that chapter was simplified because I didn't show ...