I am from Germany and my provider is "Kabel Deutschland", a rather big one. I write this in case other users here have had the same problems that I had.

I was experiencing massive lag for several weeks now. Using nettest I found out that the bandwidth dropped down to 3kb/s exactly at the same time every day. That is 18:00 - 00:00 (06pm- 00am) and nearly for the whole weekend. Traceroute and several speedtests with benchmark sites showed no problems, it seemed only to be with STO.

Now when I googled for the downtimes in connection with my provider I found a filesharing forum that lead to the answer. I very rarely use bittorrent and othwise I run no file sharing applications at all so I didn't care so far.

It appears that if a user runs bittorrent anytime this user gets flagged for timed bandwidth throtteling. Maybe other services trigger that too. As the IP address usually does not change (even not after rebooting the modem), this flag remains "forever" no matter if the user causes any traffic at all. Moreover HTTP traffic is not affected that's why the speedtest sites didn't show a slow connection and the bandwidth reduction seems also to be limited to some "nodes" like from Europe to USA but not within Germany or even Europe. I also read the ISP usally denies the existence of such a mechanism. All this made it difficult the find out that it finally indeed was the fault of the ISP.

Now to the solution. You can only get a new IP address quickly if you change the MAC address of the connected router. Moreover it seems that the new MAC address has to be different in at least 2 parts. Voila bandwidth throttle is gone! :-(

I hope this can help other people with the same provider too. To the Cryptic support I can only say: Sorry for inconveniences!