Why does 'ifconfig wlan0 -promisc' fix my wifi problem?

I have the Alfa Network AWUS036H USB adapter. It worked splendidly under Linux in the 2.6 kernel days and just as well in Windows 7.

I recently switched from Windows to LMDE, which has a 3.2 series kernel now. I think the RTL8187 driver has regressed since 2.6, because the results were bad. It'd work fine for few minutes of light to moderate load. Then HTTP connections started timing out: First the sites I was using most would stop responding, and eventually I couldn't reach any site. All the while, my link strength stayed very strong.

For a while, my solution was to remove and readd the rtl8187 module, or to unplug the adapter and plug it back in. Annoyed by that routine, I tried to analyze the problem in Wireshark. I know little of networking internals, but I noticed that whenever I'd start a Wireshark capture, the problem would temporarily desist. Apparently, moving the interface into promiscuous mode reset something.

I established a cron job to move the interface into promiscuous mode and back every minute. But that was actually disruptive; my video streams would hiccup every minute. Finally I found that just unsetting promiscuous mode every minute keeps it healthy. Whether something else is setting promiscuous mode in the meantime, I have no idea.

What I want to know is why that fix works, what that tells us about a possible systemic fix for the RTL8187 driver, and if there might be any subtle side effects I should be wary of. (I've noticed no side effects after three days, though.)

It look like the RTL8187 driver has problem. Does you use lastest driver?

Yeah, I even tried using compat-wireless drivers. Anyway, I have a satisfactory workaround already. I want to know what it all suggests is wrong with the driver.

Mine worked great on windows 7 but I installed Ubuntu 12.04(3.2.0-27-generic) last week. Now I have the problem you describe where it says I have a strong connection but all my connections would time out after an hour or so, sometimes less. The only fix I found was rebooting my computer. I will try out what your doing next time it happens to me. Please come back and let me know if u find a permanent fix for this problem. I posted on launchpad.net trying to get help with the problem but have yet to find a solution. Here is my post: https://answers.launchpad.net/ubuntu/+question/203845

I've found that my fix works pretty well, but it's not airtight. It seems like the more fragmentation network conditions induce, the more often I will have to reload the module to work again. At most places, though, I never have to do that.

I've read so many anecdotes similar to mine that I feel sure it's a driver bug. But as I said, I don't know much about networking, and so I haven't been able to identify any specific technical stuff that I could paste into a bug report.

There's a new Linux kernel out that is supposed to address buffer bloat problems. Perhaps ours is a buffer bloat problem, and the new kernel will fix it. Hope so! I'll find out in the next couple months, I guess.

Noah in comparison with me you are a telecom engineer.....I have the same antenna, that allows me to browse at will.
ITS WILL!

I temporarily fixed the problem on Ubuntu some times ago, I can't even remember what I did.
than the problems came back.

I'm on Fedora now, and I just don't know what to do

how did you solved?

please, talk as if I was totally ignorant