Hey, thanks for your comment-you're right there aren't too many details on the protocol changes we made in part because we will follow up on that in another post. This blog post was getting too long as it is and we wanted to focus more on the need to simulate and test. Your comments on the hacker news post you link too actually partially served to inspire us!

I am glad to have somebody acting on this stuff.

The original design for FASP's flow control was developed in China and applied in a router: you would have one at each end, and it would spoof TCP for clients. That was a huge flop, because it didn't say Cisco on the nameplate.

The Aspera principals realized they could implement it in user space using UDP, bypassing the network infrastructure purchasing cabal, and sell directly to the users who had data to move.

I always wanted to get the astronomy community using it (e.g. to Antarctica and Atacama, Chile) under a free license, but never quite got there.