I'd read this blog post by the owner of UK ISP Andrews & Arnold earlier this evening.
This is a problem. TCP does not do 20Mb/s over 700ms. Do the sums. It means 1.7MB of transmit buffer at the sender per TCP session. I checked, and the config on a typical linux box was 128kB. You can put it up, and use window scaling (TCP only does 64KB without it) but that would mean reconfiguring every server on the internet to which you wish to communicate.