Re: [Bloat] Educate colleges on tcp vs udp

[Erik Auerswald <auerswal@unix-ag.uni-kl.de>]

Hi Erik,

On 21.05.21 08:01, Taraldsen Erik wrote:
> 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.
> 
> 
> 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.

You could take a look at:

"Video Notes: Tanenbaum, Wetherall Computer Networks 5e"

https://media.pearsoncmg.com/ph/streaming/esm/tanenbaum5e_videonotes/tanenbaum_videoNotes.html

Specifically the sections "Transport Layer, Reliable Transport"
and "Congestion Control."

For reading material I can recommend "The TCP/IP Guide"
http://www.tcpipguide.com/ .

You can find a curated list of freely available networking
(i.e., packet switching and TCP/IP) textbooks in the section
"Textbooks and Other Books You Should Read" of the "How
Networks Really Work" webinars from Ivan Pepelnjak:

https://my.ipspace.net/bin/list?id=Net101#TEXTBOOK

> 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.

Packet switching, and the transport services built on top,
e.g., TCP, are different from other information transport
systems.  They have evolved over decades and have become
quite complex, with surprising interactions (e.g., bufferbloat).

IP data over mobile networks is even more complex, and it
differs for the different mobile network generations.

Thus I do not think one should expect to really understand
it immediately.  Jumping right into the middle with TCP ACKs,
used for both reliability and flow control, and as part of
the congestion control scheme used on the Internet, without
looking at the fundamentals first, seems quite hard.

My advice, if I may, would be to view IP/TCP as something
new to your colleagues.  It would seem advisable to me to
start by learning the fundamentals.  This would most probably
require quite some time, though.

After achieving some confidence regarding the fundamentals,
I recommend taking a look at the four links from:
https://www.unix-ag.uni-kl.de/~auerswal/networkers_essential_reading/
(especially the paper "End-to-End Arguments in System Design"
http://web.mit.edu/Saltzer/www/publications/endtoend/endtoend.pdf).

HTH,
Erik