For the longest time I had a 24/2 Mbps ADSL line, and had zero problems in both Windows and OpenSuse 13.1.
Some time ago, however, this housing company switched to a 100/10 VDSL service (which also meant a forced change from an ADSL modem to a VDSL one).
Immediately after the switch I noticed bad connection problems both in Windows and Linux. The connection would work mostly, and pretty fast (over 85/10 Mbps download/upload rates according to speedtest.net), except that the connection would halt for several seconds on a semi-regular basis. The connection would work just fine, and then it would halt for a second or two, and then continue. Sometimes the pause would be significantly longer. The problem was significantly worse on Linux than on Windows, but it appeared on both.
The problem was highly perplexing, because it happened on my PC only. I did not notice any such problem with any other device using the same connection. And I tried everything I could think of (other ethernet cables, using a PCI ethernet card instead of the motherboard’s one and so on and so forth; nothing made any difference.)
Even more perplexingly, the problems seemed to vanish from Windows after some weeks. I have no idea why or how. I have not noticed any problem for months on the Windows side. The connection seems to be fast and stable, without the pauses.
Likewise the problems have diminished somewhat on the Linux side, but not gone away completely. While it’s better, it’s still so bad as to make Linux almost unusable. Just eg. watching YouTube videos is highly annoying because it will often get stuck, either just starting the video, or in the middle of it, loading it. When running the speedtest.net test, the connection will often show the 85+ Mbps, but sometimes get stuck in the middle of it for several seconds. It’s highly annoying to browse the internet, with the constant pauses. It’s hard to describe how annoying it is, but it makes it almost unusable, really.
I know I’m pretty much grasping at straws here, and this might be a completely hopeless endeavor, but I’m hoping that somebody could have some idea of what to do next. The problem is highly strange and perplexing, and at this moment seems to affect only Linux.
As said, I don’t believe it to be a hardware problem. As said, whether using the MB’s ethernet chip, or a separate PCI ethernet card, it makes no difference. I have tried like 4 different ethernet cables, and it makes no difference. And I have not noticed the problem in any other device than my PC, and the connection seems to be working fine on the Windows side (even though, as said, strangely the problem was similar there at first, but somehow fixed itself later for unknown reasons). I have no idea what could be causing this, or how to find out.