[e2e] TCP "experiments"

Jon Crowcroft Jon.Crowcroft at cl.cam.ac.uk
Thu Aug 1 02:38:38 PDT 2013


yes, fairness is a key idea which has to be linked with some accountable entity

here's an interesting relevant paper (i think:)
http://www.sigcomm.org/ccr/papers/2008/January/1341431.1341434

In missive <2A89DA46-85CA-4261-AF2E-D15DE4222ED4 at tlc.polito.it>, Marco Mellia typed:

 >>If you want an example where a change would be not "fair", you can =
 >>consider YouTube.
 >>Now they start to use more than one TCP connection to serve the video.
 >>This avoids that the application gets stuck because the TCP connection =
 >>gets stuck.
 >>In case of competing traffic (and congestion), YouTube client will =
 >>download in parallel from multiple connections (we have seen up to 5).
 >>Thus sharing capacity is not fair against other concurrent traffic.
 >>You may say that Video is not best effort, so why not.
 >>But in a scenario where you use YouTube and I use MyTube, you'll see, =
 >>and I'll not see :(
 >>You are more aggressive, and get a larger share of capacity.
 >>
 >>Same for TCP initial window. You use 10, I use 2. You are more =
 >>aggressive. I suffer from additional losses/delay because of you (in =
 >>case we share the same link).
 >>
 >>As said, weighting the pros against the cons is not easy.
 >>
 >>Anyway, I found it funny that we can discuss this forever. But actually =
 >>no one has the right/power/control of imposing anything on the Internet.=20=
 >>
 >>Basically, it's a perfect anarchy, where everyone is allowed to =
 >>do/deploy whatever he thinks it's good for him.=20
 >>I push more, I get more. I don't care if you get hurt=85
 >>Would be nice to have a system where some judge can say that you are =
 >>pushing too much, and provide a punishment for you. But this seems quite =
 >>impossible here=85
 >>
 >>Ciao
 >>M
 >>
 >>
 >>
 >>> In missive <FFE1446C-A44E-40E8-BAF4-BFF44082BFEE at tlc.polito.it>, Marco =
 >>Mellia typed:
 >>>=20
 >>>>> Jon,
 >>>>>=20
 >>>>> I think no one is saying that big companies are doing dumb things. =
 >>It's =3D
 >>>>> just that the Internet is a really shared infrastructure.
 >>>>> Unless resources are infinite (which may be actually the case for =
 >>Google =3D
 >>>>> :)), gaining something somewhere comes at the expenses of loosing =3D
 >>>>> something else somewhere else.
 >>>>>=20
 >>>>> Considering TCP, it is easy to show that "I can gain". It is much =
 >>harder =3D
 >>>>> to show "who else is loosing".
 >>>>> And weighting the plus and the minus is even more complicated.
 >>>>>=20
 >>>>> M
 >>>>>=20
 >>>>>=20
 >>>>> --=3D20
 >>>>> Marco Mellia - Assistant Professor
 >>>>> Dipartimento di Elettronica e Telecomunicazioni
 >>>>> Politecnico di Torino
 >>>>> Corso Duca Degli Abruzzi 24
 >>>>> 10129 - Torino - IT
 >>>>> Tel: +39-011-090-4173
 >>>>> Cel: +39-331-6714789
 >>>>> Skype: mgmellia
 >>>>> Home page: http://www.tlc-networks.polito.it/mellia
 >>>>>=20
 >>>>> On Jul 30, 2013, at 1:34 AM, Jon Crowcroft =
 >><Jon.Crowcroft at cl.cam.ac.uk> =3D
 >>>>> wrote:
 >>>>>=20
 >>>>>> the nice thing about a lot of the big cloud/web service outfits=3D20
 >>>>>> is that they run a huge _range_ of applications so a point =
 >>solution=3D20
 >>>>>> tcp optimised for just one thing that=3D20
 >>>>>> harmed the common case uses of TCP would be ruled out -=3D20
 >>>>>> =3D20
 >>>>>> if you think about the mix of map/reduce,=3D20
 >>>>>> video streaming, social net, searches, gmail, gfs, google docs, etc =
 >>=3D
 >>>>> etc=3D20
 >>>>>> (and similar mixes for microsoft bing + hotmail + azure etc;=3D20
 >>>>>> and similar for apple iCloud, appstore, and similar for,
 >>>>>> oh, i dunno, maybe even facebook),=3D20
 >>>>>> then I doubt very much we'd see them do something
 >>>>>> as narrowly dumb as people seem to imply here=3D20
 >>>>>> (or deploy someone else's dumb narrow hack either)....
 >>>>>> =3D20
 >>>>>> as for impact between different cloud/web service providers
 >>>>>> (e.g. google being smart enough to optimise a TCP hack for all that =
 >>=3D
 >>>>> stuff
 >>>>>> but still harm Amazon's traffic for book/cd buying, EC2, cloud =
 >>music =3D
 >>>>> player
 >>>>>> etc etc, that would be incredibly ingeneiously dumb,=3D20
 >>>>>> but also unlikely, since a major google's revenue depends on=3D20
 >>>>>> people finding stuff on _other servers,=3D20
 >>>>>> and finding those other services useful,=3D20
 >>>>>> so it would be kind of silly to auction advert space to the highest =
 >>=3D
 >>>>> bidder=3D20
 >>>>>> iand deliver those adverts in a way that broke the advertised =3D
 >>>>> things....
 >>>>>> =3D20
 >>>>>> [I suppose you could deliver adverts that broke TCP services to
 >>>>>> servers that hadn't paid you to advertise them - that'd be pretty
 >>>>>> super duper whacky type of cyberwarfare game some folks at the NSA
 >>>>>> probably have fun thinking up.....
 >>>>>> =3D20
 >>>>>> maybe Huawei could deploy some DPI-based filter to harm succesful =3D=
 >>
 >>>>> businesses only
 >>>>>> so as to bring down the whole capitalist imperialist western =3D
 >>>>> civilisation....oh no,
 >>>>>> wait, they need our net to work so they can sell us their =
 >>routers...
 >>>>>> =3D20
 >>>>>> In missive <2EBB07CA-C011-4DC4-AACD-5A9D959C59D7 at isi.edu>, Joe =
 >>Touch =3D
 >>>>> typed:
 >>>>>> =3D20
 >>>>>>>> =3D20
 >>>>>>>> =3D20
 >>>>>>>> On Jul 29, 2013, at 11:14 PM, Jon Crowcroft =3D
 >>>>> <Jon.Crowcroft at cl.cam.ac.uk> wro=3D3D
 >>>>>>>> te:
 >>>>>>>> =3D20
 >>>>>>>>> google have extremely good instrumentation -
 >>>>>>>> =3D20
 >>>>>>>> They can now see how my PC talks to amazon.com now?
 >>>>>>>> =3D20
 >>>>>>>>> their shareholders would get upset if they deployed things that =
 >>=3D
 >>>>> broke
 >>>>>>>>> the world badly -
 >>>>>>>> =3D20
 >>>>>>>> Even if they made Google 0.01% faster? And increased ad revenue =
 >>as a =3D
 >>>>> result?=3D3D
 >>>>>>>> And stock value or dividends?
 >>>>>>>> =3D20
 >>>>>>>>> that's the NSA's job.
 >>>>>>>> =3D20
 >>>>>>>> Sound like you're referring to my first point above :-)
 >>>>>>>> =3D20
 >>>>>>>> Joe=3D3D20
 >>>>>>>> =3D20
 >>>>>> =3D20
 >>>>>> cheers
 >>>>>> =3D20
 >>>>>>  jon
 >>>>>> =3D20
 >>>>>=20
 >>>=20
 >>> cheers
 >>>=20
 >>>   jon
 >>>=20
 >>

 cheers

   jon



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