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<p>Not a brilliant idea on my part to send a question to the list just hours before I go on a multiday trip without email access. So this is a group thank you for all the responses - off and on list. I'll need some time to review the response.</p>
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<p>-Erik<br>
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<div id="x_divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>Fra:</b> Erik Auerswald <auerswal@unix-ag.uni-kl.de><br>
<b>Sendt:</b> mandag 24. mai 2021 20.51.07<br>
<b>Til:</b> Taraldsen Erik; bloat<br>
<b>Emne:</b> Re: [Bloat] Educate colleges on tcp vs udp</font>
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<div class="PlainText">Hi Erik,<br>
<br>
On 21.05.21 08:01, Taraldsen Erik wrote:<br>
> I'm getting some traction with my colleges in the Mobile department on measurements to to say something about user experience. While they are coming around to the idea, they have major gaps in tcp/udp/ip understanding. I don't have the skill or will to
try and educate them.<br>
> <br>
> <br>
> Is there good education out there - preferably in the form of an video - which I can send to my co workers? The part of tcp using ack's is pure magic to them. They really struggle to grasp the concept. With so basic lack of understanding it is hard to
have a meaningful discussion about loss, latency an buffering.<br>
<br>
You could take a look at:<br>
<br>
"Video Notes: Tanenbaum, Wetherall Computer Networks 5e"<br>
<br>
<a href="https://media.pearsoncmg.com/ph/streaming/esm/tanenbaum5e_videonotes/tanenbaum_videoNotes.html">https://media.pearsoncmg.com/ph/streaming/esm/tanenbaum5e_videonotes/tanenbaum_videoNotes.html</a><br>
<br>
Specifically the sections "Transport Layer, Reliable Transport"<br>
and "Congestion Control."<br>
<br>
For reading material I can recommend "The TCP/IP Guide"<br>
<a href="http://www.tcpipguide.com/">http://www.tcpipguide.com/</a> .<br>
<br>
You can find a curated list of freely available networking<br>
(i.e., packet switching and TCP/IP) textbooks in the section<br>
"Textbooks and Other Books You Should Read" of the "How<br>
Networks Really Work" webinars from Ivan Pepelnjak:<br>
<br>
<a href="https://my.ipspace.net/bin/list?id=Net101#TEXTBOOK">https://my.ipspace.net/bin/list?id=Net101#TEXTBOOK</a><br>
<br>
> I don't mean to talk them down to much, they are really good with the radio part of their job - but the transition into seeing tcp and radio together is very hard on them.<br>
<br>
Packet switching, and the transport services built on top,<br>
e.g., TCP, are different from other information transport<br>
systems. They have evolved over decades and have become<br>
quite complex, with surprising interactions (e.g., bufferbloat).<br>
<br>
IP data over mobile networks is even more complex, and it<br>
differs for the different mobile network generations.<br>
<br>
Thus I do not think one should expect to really understand<br>
it immediately. Jumping right into the middle with TCP ACKs,<br>
used for both reliability and flow control, and as part of<br>
the congestion control scheme used on the Internet, without<br>
looking at the fundamentals first, seems quite hard.<br>
<br>
My advice, if I may, would be to view IP/TCP as something<br>
new to your colleagues. It would seem advisable to me to<br>
start by learning the fundamentals. This would most probably<br>
require quite some time, though.<br>
<br>
After achieving some confidence regarding the fundamentals,<br>
I recommend taking a look at the four links from:<br>
<a href="https://www.unix-ag.uni-kl.de/~auerswal/networkers_essential_reading/">https://www.unix-ag.uni-kl.de/~auerswal/networkers_essential_reading/</a><br>
(especially the paper "End-to-End Arguments in System Design"<br>
<a href="http://web.mit.edu/Saltzer/www/publications/endtoend/endtoend.pdf">http://web.mit.edu/Saltzer/www/publications/endtoend/endtoend.pdf</a>).<br>
<br>
HTH,<br>
Erik<br>
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