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there are 2 buildings (A and B). In bldg A is an open WLAN (which I'm allowed to use btw). In bldg B is a computer that I want to connect to that network.

So I flashed an old D-Link DIR-300 AP with DD-WRT, mounted it to the wall (bldg B) near a window, attached a 13 dBi directional antenna (pointing to bldg A) and configured it as AP client in that wireless network. Then there's another AP, connected to the D-Link AP, acting as standard access point, which the computer is connected to.

That's basically working so far, but:

  1. Every now and then the connection is lost. Not the connection between the computer and the D-Link (I can access the DD-WRT admin page normally) or the connection between the D-Link and the WLAN (in Status - Wireless it says it's still connected to the network), but when I want to access a web page (which only works if I'm connected to the wireless network from bldg A), my Firefox keeps "Looking for" (name resolution) without finding anything. When I reset the D-Link (power off, power on) in this situation, after some moments, everything's working fine again (Internet access). I've no idea why this is happening, but usually it's at most every few weeks (most times when nobody was using the computer, so no traffic).
  2. Compared to the connection speed when I connect directly to the WLAN in bldg A (Laptop), the speed in bldg B is rather slow, but I have the impression that this difference is worse in the last few days. A few minutes ago, I got 582 KB/s down and 911 KB/s up in bldg A (directly/laptop) and 84 KB/s down and 9 KB/s up in bldg B. The speed in bldg B used to be way higher (I remember 200 KB/s up) while the actual network speed in bldg A was lower than it is now (close to those 200). I'm aware that the wireless connection between those buildings should slow things down, but I'm wondering why this difference has become that extreme.

Thanks for any tips...

Update: I currently want to upload a large file (1.5 GB) via FTP (FileZilla). Since that caused the D-Link to disconnect (as described in first post), I took my laptop to bldg A, connected directly to the original WLAN (bypassing my D-Link) and tried the same upload. Guess what - same issue: At some point the connection is dead (at this point I would have reset my D-Link if I was connected to it). Just as the D-Link, my laptop is still connected, but not even name resolution is working ("Looking for..." in Firefox). After reconnecting, it's working again. Maybe my D-Link isn't the problem at all...

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closed as off topic by Michael Hampton, HopelessN00b, Scott Pack, RobM, Sven Oct 28 '12 at 0:20

Questions on Server Fault are expected to relate to server, networking, or related infrastructure administration within the scope defined by the community. Consider editing the question or leaving comments for improvement if you believe the question can be reworded to fit within the scope. Read more about reopening questions here.If this question can be reworded to fit the rules in the help center, please edit the question.

I have seen poor power cause the router to seem to be "working" but reboot fixes the issue. Installed a simple UPS and issue was resolved. It seemed to be more low voltage than high.

Speed could be total number of users. How many sharing and what are they downloading. Casual browsing will have less imapct that say torrent users or someone streaming video.

One other thought is another AP that is on a conflicting channel. Had this at one office and it seemed like the wireless router in another unit would change channel for some reason and we would have a conflict. Several site surveys and we finally seem to have a channel that the other device does not try. Try a site survery a few times and see if there is a conflict.

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Interesting idea ... but it's not possible to mount a UPS on the wall and there isn't really place for that on the floor. Is there a way to check if such a voltage issue has caused a (temporary) problem on the D-Link? Putting a UPS there for a few weeks seems like the last thing I'd try... – basic6 Mar 8 '11 at 19:42
Perhaps a UPS just in the same area. If it beeps or alerts you would know there are issues. Even a voltmeter to see if voltage is normal from time to time. – Dave M Mar 8 '11 at 20:28

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