From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from tn-mailgw-03.telenor.no (tn-mailgw-03.telenor.no [153.110.76.6]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 679C83B2A4 for ; Tue, 25 May 2021 02:38:15 -0400 (EDT) IronPort-SDR: UZ0lSbdksuBHo8NFNFd8BgW0qPkgF/d4WlHksh/GxF/bs99KMbEExhqVm1465Wam8oIB3gWhOH qDZQChwKLRgEEsLEhvt5eGwiCrUQEnlu6ZeJ7yS5vbdkdXwXMxS05uORhx0wHko1MD2xMauwh0 mUT6utDPRjADrGG+gpS3EqkSwYvnu2YW1TF4+yn2PQ3vG9E/MzGtM89CVXxK3L5z5Ap8OzrvDH oOwZhTzWdRdKDfMqBAyw88Dg7PsWLnrrwjMiPXo/UkWJXxKgntv1qVDob4vq9/XrdIP8dOjitC 96c= X-IronPort-AV: E=Sophos;i="5.82,327,1613433600"; d="scan'208,217";a="81315244" Received: from tns-sko-24-200.corp.telenor.no ([10.179.59.68]) by tn-mailgw-03.corp.telenor.no with ESMTP; 25 May 2021 06:38:14 +0000 Received: from TNS-SKO-24-207.corp.telenor.no (10.179.59.75) by TNS-SKO-24-200.corp.telenor.no (10.179.59.68) with Microsoft SMTP Server (TLS) id 15.0.1497.18; Tue, 25 May 2021 08:38:11 +0200 Received: from outlook.telenor.no (10.179.127.57) by TNS-SKO-24-207.corp.telenor.no (10.179.59.75) with Microsoft SMTP Server (TLS) id 15.0.1497.18 via Frontend Transport; Tue, 25 May 2021 08:38:11 +0200 Received: from pwpvn2209ex001.nxvp.net (10.149.139.134) by pwpvn2209ex004.nxvp.net (10.149.139.137) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2242.10; Tue, 25 May 2021 08:38:10 +0200 Received: from pwpvn2209ex001.nxvp.net ([10.149.139.134]) by pwpvn2209ex001.nxvp.net ([10.149.139.134]) with mapi id 15.01.2242.010; Tue, 25 May 2021 08:38:10 +0200 From: Taraldsen Erik To: Erik Auerswald , bloat Thread-Topic: [Bloat] Educate colleges on tcp vs udp Thread-Index: AQHXUM3oyhlRw6MskkGA72fy99biQarzvuXX Date: Tue, 25 May 2021 06:38:10 +0000 Message-ID: <58daea37ad4b4adf9db6a95f1377143e@telenor.no> References: , In-Reply-To: Accept-Language: nb-NO, en-US Content-Language: nb-NO X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.149.139.250] x-tm-snts-smtp: D75CB48315808ADB842EC51F65E71AD707606DD54F1205881856C2246F83E02E2000:8 Content-Type: multipart/alternative; boundary="_000_58daea37ad4b4adf9db6a95f1377143etelenorno_" MIME-Version: 1.0 X-Mailman-Approved-At: Tue, 25 May 2021 04:38:15 -0400 Subject: Re: [Bloat] Educate colleges on tcp vs udp X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 25 May 2021 06:38:15 -0000 --_000_58daea37ad4b4adf9db6a95f1377143etelenorno_ Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Not a brilliant idea on my part to send a question to the list just hours b= efore I go on a multiday trip without email access. So this is a group tha= nk you for all the responses - off and on list. I'll need some time to rev= iew the response. -Erik ________________________________ Fra: Erik Auerswald Sendt: mandag 24. mai 2021 20.51.07 Til: Taraldsen Erik; bloat Emne: Re: [Bloat] Educate colleges on tcp vs udp Hi Erik, On 21.05.21 08:01, Taraldsen Erik wrote: > I'm getting some traction with my colleges in the Mobile department on me= asurements to to say something about user experience. While they are comin= g 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 mag= ic 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, la= tency an buffering. You could take a look at: "Video Notes: Tanenbaum, Wetherall Computer Networks 5e" https://media.pearsoncmg.com/ph/streaming/esm/tanenbaum5e_videonotes/tanenb= aum_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=3DNet101#TEXTBOOK > I don't mean to talk them down to much, they are really good with the rad= io part of their job - but the transition into seeing tcp and radio togethe= r 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 --_000_58daea37ad4b4adf9db6a95f1377143etelenorno_ Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable

Not a brilliant idea on my part to send a question to the list just hour= s before I go on a multiday trip without email access.  So this is a g= roup thank you for all the responses - off and on list.  I'll need som= e time to review the response.



-Erik

Fra: Erik Auerswald <a= uerswal@unix-ag.uni-kl.de>
Sendt: mandag 24. mai 2021 20.51.07
Til: Taraldsen Erik; bloat
Emne: Re: [Bloat] Educate colleges on tcp vs udp
 
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 a= re coming around to the idea, they have major gaps in tcp/udp/ip understand= ing.  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/e= sm/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=3DNet101#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 toge= ther 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).<= br>
HTH,
Erik
 --_000_58daea37ad4b4adf9db6a95f1377143etelenorno_--