Slow-Start Follow-Up

I guess it was a slow news day today, because my post on how sites are goosing the tcp slow-start algorithm has received a couple of orders of magnitude more attention than I expected. On the one hand, it's been pretty cool for my second blog post ever to make it to the front page of HN, reddit, and Slashdot. On the other hand, I feel awkward about the whole thing because, while I'm reasonably familiar with the issues I'm talking about, I'm by no means an expert. And in retrospect, I probably should have used a less inflammatory title for the post (though it's a little late to retract it now, so I'll leave it as is).

So, this is probably a good time to couch my observations with a few qualifications:

1. My analysis wasn't particularly rigorous, and I didn't even save my data (other than in the blog post). If I had know how much attention this would get, I would have done a lot more test runs of more sites from more locations (and I may as a follow-up).
2. It's entirely possible that I'm misinterpreting what I saw. In particular, there may be some cwnd caching going on somewhere a la RFC-2140. However, since Google mentions that they don't believe cwnd caching is effective in their presentation on IW10, I think that's unlikely in the www.google.com case. It does, however, seem like a plausible explanation for the www.microsoft.com behavior.
3. A number of commenters have taken issue with my invocation of network neutrality. They make a good point. This isn't a net neutrality issue, strictly speaking. It is (arguably) an issue of network fairness, however.

Those points aside, my goal was to spark some discussion in the web development community around whether it's time for widespread deployment of a larger IW in spite of the fact that the tcp community is still divided on the issue. That mission, at least, seems to have been accomplished.