It's not the tbb speedtester itself, that's perfectly capable of handling FTTC speeds. My hunch is that there's something odd about the routing of data from VDSL lines, I never saw this effect on ADSL2+. But it's no more than a hunch, I don't know enough about networking on a national scale for it to be more than that.
I don't think its the routing tech or the DSL that affects it. I'm sure its more local to PC setup, either security software or [censored] drivers etc. Or some ISP rate limiting per stream.
I can occasionally get a 20mbps sync on my line (3db margin, fast path, adsl2+) and with BE and my hardwired Core i7 desktop there is virtually no difference in the testers.
So I have no problem with the owners saying the tester works (and I've seen it work on a 20megabit corporate service without problem) and I suspect its just congestion. Maybe multiple streams handle congestion better.
Edit to add - multi streams simulates much more general web surfing; so to say the single stream is better assumes downloading without any accelerator. Many sites force you to use their accelerator (e.g. Adobe, or Microsoft).
--
James -
be* pro, on THFB exchange with a Draytek 2820Vn and a BeBox (585v7)
BQM
Edited by jchamier (Sat 13-Nov-10 17:50:57)