Let's dig into TCP SACK using Wireshark. Get out your copy and let's start digging! https://youtu.be/VERgI8QaYPY …
[Read more...] about How TCP Works – Selective Acknowledgment (SACK)
Videos
How TCP Works – No Operation Field
Hey packet people! If you have ever had to analyze a TCP connection, you have definitely seen a three-way handshake. In that handshake, both TCP stacks will exchange the options they are open to use for the connection. In the options field, you may also see several instances of the No-Operation …
How TCP Works – MTU vs MSS
In this video we will take a look at the TCP Maximum Segment Size value and how it works, contrasting it with the Ethernet/IP MTU value. We will also take a look at why these values are different and how the network can adjust MSS along the path, and how that impacts each end of the …
How TCP Works – Window Scaling
In this video we will take a look at how the TCP Window Scaling option works. In short, this option allows a TCP receiver to advertise a receive window of up to 1GB. But how does this feature actually work? How does Wireshark come up with the Calculated Window Size value? This video will …
How TCP Works – The Receive Window
What does that Window field in the TCP header do? Many people ask this question after capturing a trace file with Wireshark. What is the TCP Window? How does it work? How can I use it to troubleshoot performance problems? We will answer these questions and more in this nine minute …
How TCP Works – Acknowledgment Numbers
Let's learn more about TCP. So far, we've looked at the handshake process and how sequence numbers work. Now, let's check out how the acknowledgment process works with TCP. After all, this is a critical component of making TCP a connection-oriented, reliable transport protocol. Understanding …