I had this problem some time ago between a linux server and windows,
I applied the correction of the client support on my server linux and this corrected my problem of speed
" " Haley WebbFebruary 27, 2017 09:02
Hello,
Thank you for the report.
Peers are located in different networks, right?
We have checked the logs, and there are no any errors - files are just being synced at a max speed available at the given moment. We've noticed though that speed usually drops when peers connect over UDP protocol, so it's possible that ISP might be shaping the traffic. you can force TCP only: stop Sync, go to storage folder, find file debug.txt, open it and put 2 as the second line instead of 0 (zero) there. Start Sync. Do that on both peers.
If that does not help, revert it back to zero and give more details about your network. Is there any reason why DEDIBOX considers its local and public IP the same - 195.154.xx.xx? " "