[v6test] Test download server

[Kevin Day]

I'm starting to do some performance/load testing of our download  
cluster. If anyone wants to see what kind of speeds they're getting  
from us right now, there are a couple of videos posted at http://testdownload.ipv6experiment.com 
. Accessible both over v4 and v6, to help with speed comparisons.

If you're getting really bad or really good download speeds off that,  
let me know off list. I'm at the point where I can start looking for  
routing/performance problems to get them fixed before it launches.

Teredo users may get some really bad performance right now, this is a  
known problem and I'm working on a solution.

Right now I'm just testing our monitoring system. Each download is  
logging things like MSS, packet loss, window size, etc. I'm not too  
worried about problems with the video compression or content itself  
yet, that comes next!

Don't spread the URL all over the place, please. :)

-- Kevin