From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io1-xd31.google.com (mail-io1-xd31.google.com [IPv6:2607:f8b0:4864:20::d31]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id BD4073B29D for ; Wed, 26 May 2021 14:09:57 -0400 (EDT) Received: by mail-io1-xd31.google.com with SMTP id o21so1955281iow.13 for ; Wed, 26 May 2021 11:09:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=0XFFA98sqr8XnjlUh+N/TVs+pTRrNTIP1Yd5RbGgulk=; b=U2JzbSo4M62RA+qb7rBallVC11GXqmhQ/8DOobrKf6FRJNntQgczJocIjLqjgzc2/5 L81z5QJoOkC6A5g1iIk5KWOmWImOEB6HFF7q0nQYnC2NeTp2HIQ5Gl5zIE5ONX9Xvth1 vCtPPiD7UhamIaSXyxgTbzmYslz5xqkYNN+RIXZEaRPSesRqXyskTkdH3GhZjFFdhQzD 75e5MUhLP8fJRdItXYlWDHdVaT+pps3p20T9c8h54lB8nYb7wm3M5wOHYIA3xobnNfp7 gUakxQMtTgFymyKoP2bGN7JlGaFOHdj+uY4g7W2pDHh6kkwpmwMdmHSaCYCQV9+ZVXZu PMbg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=0XFFA98sqr8XnjlUh+N/TVs+pTRrNTIP1Yd5RbGgulk=; b=TIFArSYHy9AoYgRl/6YMYOT5elrMIqHqapF500/fpAs68q7vJ6hbagPu2uhDYZ60hC u477HdE6n7U3j/fSEert50qos12E1SJVAS8iNSE9D9293pP44XEL3Yg9PzK483YX3y5Q cVD8dvrvs4vTjOuUhksbUQgduOwImeWvD6UYsKqvUN7T17Fhvqi4u6rpNLEknujL75aw hk63SeXj6GbL4LUUIF2Do2AavprJ/Roik93wRprJkgEbEH+lHghwXV7haK7WoP0tEkeT UePWNaJhhszX7UuB2KAQQ4xa1ckESGlTAX5dkjsOHN7MlE3fH1NgAvJbS83rJsPrW5OC jTJg== X-Gm-Message-State: AOAM533CN/ZL0cAF0Fw9LAaoB6ZxhKfushS4qqpzROE9kPGgN6g1LKHT HamyGV3kTbpOAuudH0pOP4nzIjXCqpNMvx/0ah0wiqyjnlfvbw== X-Google-Smtp-Source: ABdhPJwspLDqNj+04seejWJ9Pf15oTdqmXVfXiXUKmYBWsluOHFJJOjPrwptOvhtOMLp0eemdAAB33G0LMlA11cDczw= X-Received: by 2002:a05:6638:22b4:: with SMTP id z20mr4374350jas.128.1622052596943; Wed, 26 May 2021 11:09:56 -0700 (PDT) MIME-Version: 1.0 References: <58daea37ad4b4adf9db6a95f1377143e@telenor.no> In-Reply-To: <58daea37ad4b4adf9db6a95f1377143e@telenor.no> From: Dave Taht Date: Wed, 26 May 2021 11:09:44 -0700 Message-ID: To: Taraldsen Erik Cc: Erik Auerswald , bloat Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable 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: Wed, 26 May 2021 18:09:57 -0000 I thought I did a good demo of ack behavior in this apnic video... https://blog.apnic.net/2020/01/22/bufferbloat-may-be-solved-but-its-not-ove= r-yet/ On Tue, May 25, 2021 at 1:38 AM Taraldsen Erik wrote: > > 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 t= hank you for all the responses - off and on list. I'll need some time to r= eview 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 = measurements to to say something about user experience. While they are com= ing 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 m= agic to them. They really struggle to grasp the concept. With so basic la= ck 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/tane= nbaum_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 r= adio part of their job - but the transition into seeing tcp and radio toget= her 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 > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat --=20 Latest Podcast: https://www.linkedin.com/feed/update/urn:li:activity:6791014284936785920/ Dave T=C3=A4ht CTO, TekLibre, LLC