In order to understand application performance across the network, we first have to understand the basic mechanisms. In this case that foundation is built on TCP, and, more specifically, the built-in TCP Performance Options. There are many things that can be done in an application to improve performance. There are also several options from a network perspective, and more still in the operating systems. However, these all rely on the underlying protocol.
*Disclaimer: all captures in this post were anonymized using TraceWrangler. I was recently asked to help with a performance issue. I was informed a transfer was going to take weeks instead of a couple days as expected. The transfer rate was getting 80Mbps throughput max on a 10Gbps connection. So, I setup captures at both ends and got to work. This is just a quick summary of that work with the classic tell-tale signs of a performance problem.