He's a Swedish national, his host is in Sweden. You can determine that from the .se at the end of the domain, the lookup of the domain name which gives you an IP address attached to a router in Stockholm.

Sweden is a fairly large country but not nearly as large as the continental US, so in flight time of packets on a single wire is going to be limited to ~half the cross section of Sweden, say 500 km or so rather than the thousands of kilometers from your example. Broadband is extremely common in Europe with Sweden as the leading country wrt to broadband penetration.

If he was testing from a location very far away from his local server I would assume (yes, that's a risk but I'll take it) that he would have mentioned that in the article.

The default is that people that are from Sweden and that host their machines in Sweden are themselves currently in Sweden.

If he is on a very slow link (which is always possible) then he should have mentioned this in the article, and he probably should have done a traceroute -n to rule out that he's not using a congested hop somewhere along the way.

The virtual server is most likely the culprit, that's why I said 'the result is not as hot as it seems'. My guess is that there is some underlying artifact here but there is not enough info in the article to figure out what that is. A real analysis would require much more information.

I ran the same tests in the article (minus the virtual severs) on two links that I control and saw a very minimal improvement, another reason to write 'not as hot as it seems'.

You can repeat all of this in a couple of minutes.

So, in closing: if you are going to make blanket statements about TCP performance you should either give all the particulars or I will assume reasonable defaults in trying to repeat your experiment.

Both the title here and the article suggest that this is some sort of silver bullet and it definitely isn't, the specifics of the situation are what makes it work for him, there is 0 guarantee that doing the same will improve your situation, and I can think of some circumstances where it will make things worse.

'The speed of light would like a word with you' was plenty snide in its own right and that's why I responded the way I did, apologies for that but you made a huge assumption yourself by extrapolating to a situation that you are possibly familiar with rather than researching the most likely situation the author of the article was in, which to me seemed to be the way to approach the problem and verify the result.

Of course I'd be interested in a magic one line tweak that will improve all my short lived connections but this isn't it, or if it is then it will need a lot more documentation on how this can be used productively on random connections rather than the way it is used here, to optimize for a single link.

Better like that?

By the way, the google article linked below gives a much more in-depth argument for increasing the window size and also gives you a good idea on the limits of its effectiveness:

http://research.google.com/pubs/archive/36640.pdf

previous HN coverage:

http://news.ycombinator.com/item?id=1942442

And several others that I can't seem to locate.