I'm looking for QoS criteria in order to lower priority of traffic while synchronizing big files. Ubuntu One uses 443 port which cannot be good criteria because it is common for all https traffic. Destination IP is also does not seems to work because Ubuntu One uses range of IP's. Any ideas will be appreciated, Thanks, yb.
This doesn't directly answer your question, it's a workaround. You can limit the up & download rate from the U1 app like this:
This requires that you remember to switch this on and off for big files, but it should work.