I'm testing the usb server (trial) and it works good in LAN. However the situation changes in the Internet. Disk is mounted slowly (3-10 minutes) and usb disk becomes inaccessible even from host after some writing. Parted shows - Error opening /dev/sdc: No medium found. Only formatting of the disk helps.
I use ubuntu 12.04.3 as server, clients are different - Ubuntu 14.04, Windows 7(x64), Windows XP.
Configuration is default on clients.
I tried both values for TCPNoDelay on the server with the same effect.