Optimizing a high-latency connection

[Morgan]

Hi.

I'm trying som file transfers across the globe. The RTT is almost 400ms and
the transfer rate is painfully slow. There are 24 router hops on the path
and I assume most of the problem is there but I wonder if there are any
sysctl variables I can trim on my side to help this problem slightly? I seem
to understand that there need to be an ACK received for at least every other
packet or at least every 100ms for the data flow to proceed uninterrupted
but I'm no expert in this field so please correct me if I'm wrong. Assuming
this IS correct, are there any sysctl variables I can optimize to change
this behaviour or will that affect low latency connections negatively. Any
other suggestions?

Regards
Morgan