https://bugs.winehq.org/show_bug.cgi?id=44895
--- Comment #6 from mail+wine@m-reimer.de --- Thank you for your response. I could do network capturing for the "Linux side" but if this is also needed for the "Windows side", I would have to ask my brother and a beginners guide on how to capture the "right suff" would really help.
I've already disabled "tcp timestams" on both, my client PC and the router itself, but I already had the "sysctl" settings in mind. It *may* be possible that the "fix" is hidden somewhere in these settings.
Whatever it is, also "fixes" my TCP packets coming from my Linux PC and no "fixing" is needed if "real Windows" is used.
The Fritz!Box router is actually based on Linux. It has some proprietary components to do the routing but it has to use the Linux TCP stack at least for some parts of the routing process.
At least the Fritz!Box 5050 can be accessed via telnet easily. As soon as I have the required time, I'll try to dump all the sysctl settings on the Fritz!Box Linux and compare them to the OpenWRT settings.