TCP series #5: how to analyze TCP window problems

Why Should You Care About TCP Window Problems and TCP Eindowing in General?

You should care about TCP window problems because they ultimately determine the speed of data transfers and hence the experience of your users accessing the applications. In this video, you will learn more about TCP windows in general, TCP Receive windows in particular and discover how they can impact performance.

A Primer About TCP Windows

The throughput of a communication is limited by two windows: the congestion window and the receive window. The congestion window tries not to exceed the capacity of the network (congestion control); the receive window tries not to exceed the capacity of the receiver to process data (flow control). The receiver may be overwhelmed by data if for example it is very busy (such as a Web server). Each TCP segment contains the current value of the receive window. If, for example, a sender receives an ack which acknowledges byte 4000 and specifies a receive window of 10000 (bytes), the sender will not send packets after byte 14000, even if the congestion window allows it.

According to Wikipedia,

More in this series

• TCP Series #1: How to diagnose TCP Connection setup issues?
• TCP Series #2: How to close TCP sessions and diagnose disconnections?
• TCP Series #3: How to analyze TCP retransmission & duplicate ACKs?
• TCP Series #4: All you need to know about TCP Receive Windows