[e2e] TCP "experiments"

[John Day]

As those with experience in the product world or 
operational world will know, the distinction here 
is between research/development and 
product/operations.  One never does experiments 
with a production network.

There was a time when there was little choice. 
The cost of building a network of any size was 
astronomical, or at least very high.  So one had 
to do experiments on live networks and be as 
careful as you could.

Today that is not the case.  An arbitrary network 
of several hundred nodes or even a few thousand 
is not that big a deal.

Joe has a point.  An production network is no 
place to be doing experiments.  In fact, quite 
the opposite.   Experiments should be done on 
experimental networks.  (to state the opposite.)

Take care,



At 9:24 AM -0700 7/27/13, Joe Touch wrote:
>On Jul 26, 2013, at 9:48 PM, Jon Crowcroft <Jon.Crowcroft at cl.cam.ac.uk> wrote:
>
>>  while linux (pick your flavour) cubic isn't vanilla, neither is
>>  microsoft's compound tcp - the latter might have seen a bit more
>>  eval in the literature but the former has seen a lot more big iron
>>  deployment and doesn't appear to have broken the internet yet
>
>How would we know? They're not instrumented. 
>These are not experiments; they're deployments.
>
>Even Schrödinger's cat eventually sees the light 
>of day (as much as there is a cat in the first 
>place).
>
>>  (although there are rumours and reports of corner case problems)
>>  but i dont think either of these are "non tcp" - they are variants
>>  on CC behaviour....
>
>Which is a specified standard, which these mechanisms violate.
>
>You do bring up a valid point about the subject 
>line, so I've changed it for this thread going 
>forward.
>
>>  also - the ability to do any deployment testing of a new tcp in
>>  anger _requires you_ to be wireline compatible with TCP because of
>>  the "non stadard" but ubiquitous NATs and other middleboxes
>
>The environment doesn't support safe 
>experiments, but that is not a valid excuse for 
>unsafe ones.
>...
>>  so the gold standard you quite reasonably want to hold people to,
>>  to show their work doesn't do harm in the wild,
>>  requires them to do "harm" by making
>>  their new variant TCP appear chameleon like,
>>  vanilla TCP, so they can get results
>
>So they do harm to avoid doing harm?
>
>They have failed because of their first step.
>
>Joe