I have a DSL router (dlink dsl 2640b) with 802.11 b/g support.
In the last few years the DSL connection worked fine as well as the Wifi.
Recently however the wifi started to be problematic.
Apparently my neighborhood has suddenly filled up of wifi routers: every time I try to access my network I get "connection time out" from my Macs, "Error establishing connection" by windows machine, "Unable to connect" by a couple of iPhones.
I started doing some diagnosys by exclusion, here are the facts:
- the problem is platform independent
- the problem is independent of the encryption used (I've tried no encryption, WEP, WPA, WPA2 etc)
- the problem is loosely dependent on the channel used: the spectrum in the location of the router is quite filled up in the channels 4-11, channel 1-2-3 seem to be fairly free
- the problem is independent of the distance of the stations(mac,pc, iphones) from the router: I've tried from 20cm to 20m, same result
- The stations (mac,pc, iphones) do work correctly if used in other places (eg. work) and other scenarios.
- The problem does not only involve the router itself: using one of the iphone with the "hotspot" setting on would give the same result.
- by staying at ~1m of distance from the router I can see my network with a RSSI of almost -53 while all the other network are all around -75.
By excluding all of the previous I assume I am in a noisy environment and I have a small confirmation:
my home has two floors and the higher one also is the last one. By placing the router here (and thus with less interference by other AP) I can connect to the wifi by using any device (mac,pc, iphones) and any combination of channel / encryption.
I have read some thread on server fault about tuning the wifi parameters to introduce fragmentation and RTS/CTS protocol. However this did not helped much. I cannot exclude some hardware fault in the router that could have caused it not to transmit at full power. However I assume an hw fault would block the connection even when in not so noisy environment as in the upper floor.
My GUESS is that the very initial association frames of the 802.11 protocol might get lost, or the fragmentation would not be applied. Do you have any suggestion as how to further investigate this problem?